KR20130028633A - Methods of decision of candidate block on inter prediction and appratuses using the same - Google Patents

Abstract

PURPOSE: A candidate block determination method and an apparatus using the same are provided to reduce complexity by using spatial candidate prediction blocks for merging spaces and an AMVP(Advanced Motion Vector Prediction) mode. CONSTITUTION: When six merge candidates(400-450) are available after constructing a merge candidate block list, a merge candidate list is generated by successively selecting five merge candidates. When a plurality of merge candidates has equivalent motion information, a high rank merge candidate remains in the merge candidate block list and the other merge candidates are removed from the merge candidate block list.

Description

METHODS OF DECISION OF CANDIDATE BLOCK ON INTER PREDICTION AND APPRATUSES USING THE SAME}

The present invention relates to a method for determining candidate blocks in performing inter prediction and an apparatus using the method, and more particularly, to a method and an apparatus for encoding / decoding.

Recently, the demand for high resolution and high quality images such as high definition (HD) image and ultra high definition (UHD) image is increasing in various applications. As the video data becomes higher resolution and higher quality, the amount of data increases relative to the existing video data. Therefore, when the video data is transmitted or stored using a medium such as a conventional wired / wireless broadband line, The storage cost will increase. High-efficiency image compression techniques can be utilized to solve such problems as image data becomes high-resolution and high-quality.

An inter picture prediction technique for predicting a pixel value included in a current picture from a previous or a subsequent picture of a current picture using an image compression technique, an intra picture prediction technique for predicting a pixel value included in a current picture using pixel information in the current picture, There are various techniques such as an entropy encoding technique in which a short code is assigned to a value having a high appearance frequency and a long code is assigned to a value having a low appearance frequency. Image data can be effectively compressed and transmitted or stored using such an image compression technique.

An object of the present invention is to provide a method for calculating candidate motion prediction information when performing inter prediction mode to increase image encoding efficiency.

Another object of the present invention is to provide an apparatus for performing a method of calculating candidate motion prediction information when performing inter prediction mode to increase image encoding efficiency.

According to an aspect of the present invention, there is provided a method of decoding an image, including the lower left second block in a merge candidate list when the lower left second block is available, and the upper right second. If the block is available, including the upper right second block in the merge candidate list; if the lower left first block is available, including the lower left first block in the merge candidate list, upper right If the first block is available, including the upper right first block in the merge candidate list; if the upper left second block is available, including the upper left second block in the merge candidate list; If a temporal candidate prediction block is available, the method may include including the temporal candidate prediction block in the merge candidate block list. The merge candidate block list may include a fixed number of merge candidate blocks, and if the fixed number of merge candidate blocks is included in the merge candidate block list, only a fixed number of merge candidate blocks based on priority It may be included in the merge candidate block list. The merge candidate block list may include a fixed number of merge candidate blocks, and if the merge candidate blocks less than the fixed number are included in the merge candidate block list, additional merge candidates based on an additional merge candidate generation method. May be added to the merge candidate block list. The additional merge candidate generation method may be at least one of a combination merge candidate generation method, a scaling merge candidate generation method, and a zero vector merge candidate generation method.

According to another aspect of the present invention for achieving the above object of the present invention, the video decoding method predicts the motion vector calculated from the first available block determined based on the order of the lower left first block from the lower left second block. Calculating a motion vector calculated from the first block determined based on the order of the upper right second block, the upper right first block, and the upper left second block as a candidate prediction motion vector, and a temporal prediction candidate block. In this case, the method may include calculating a motion vector calculated from the temporal prediction candidate block as a candidate prediction motion vector and constructing an AMVP list using the calculated candidate prediction motion vector. The AMVP list may include a fixed number of candidate prediction motion vectors, and when the fixed number or more candidate prediction motion vectors are included in the AMVP list, only the fixed number of candidate prediction motion vectors is based on priority. Can be included in AMVP list. The AMVP list may include a fixed number of candidate prediction motion vectors, and if less than the fixed number of candidate prediction motion vectors is included in the AMVP list, the zero vector may be included in the AMVP list as a candidate prediction motion vector. Can be.

According to another aspect of the present invention for achieving the above object of the present invention, if the upper left block is available, including the upper left block in the merge candidate list, the upper left first block If available, including the upper left first block in the merge candidate list; if the upper right second block is available, including the upper right second block in the merge candidate list; If available, including the lower left second block in the merge candidate list; if the upper left second block is available, including the upper left second block in the merge candidate list and the temporal candidate prediction block is available. In one case, the method may include including the temporal candidate prediction block in a merge candidate list. The merge candidate block list may include a fixed number of merge candidate blocks, and if the fixed number of merge candidate blocks is included in the merge candidate block list, only a fixed number of merge candidate blocks based on priority It may be included in the merge candidate block list. The merge candidate block list may include a fixed number of merge candidate blocks, and if the merge candidate blocks less than the fixed number are included in the merge candidate block list, additional merge candidates based on an additional merge candidate generation method. May be added to the merge candidate block list. The additional merge candidate generation method may be at least one of a combination merge candidate generation method, a scaling merge candidate generation method, and a zero vector merge candidate generation method.

According to another aspect of the present invention, a video decoding method according to another aspect of the present invention candidates a motion vector calculated from an available first block determined based on the order of a lower left first block from a lower left second block. Calculating the motion vector calculated from the first block determined based on the order of the upper right second block, the upper left first block, and the upper left second block as the candidate predictive motion vector, and the temporal prediction candidate. When the block is available, the method may include calculating a motion vector calculated from the temporal prediction candidate block as a candidate prediction motion vector and constructing an AMVP list using the calculated candidate prediction motion vector. The AMVP list may include a fixed number of candidate prediction motion vectors, and when the fixed number or more candidate prediction motion vectors are included in the AMVP list, only the fixed number of candidate prediction motion vectors is based on priority. Can be included in AMVP list. The AMVP list may include a fixed number of candidate prediction motion vectors, and if less than the fixed number of candidate prediction motion vectors is included in the AMVP list, the zero vector may be included in the AMVP list as a candidate prediction motion vector. Can be.

According to another aspect of the present invention for achieving another object of the present invention described above, if the lower left first block and the lower left second block is available to be included in the merge candidate list, the lower left first If at least one of the block and the lower left second block is not available, the upper left second block is included in the merge candidate list in place of the unavailable block, and if neither is available, the lower left first block is substituted for the left lower first block. Including the upper left second block in the merge candidate list, If the upper right first block and the upper right second block is available, to include in the merge candidate list, the upper right first block and the upper right second If at least one of the blocks is not available, the upper left second block is included in the merge candidate list in place of the unavailable block. And when both are not available, it may comprise the step of including the steps and the temporal prediction candidate block in place of the bottom left of the first block including the top of the left second blocks to merge candidate list to the merge candidate list. The merge candidate block list may include a fixed number of merge candidate blocks, and if the merge candidate blocks less than the fixed number are included in the merge candidate block list, additional merge candidates based on an additional merge candidate generation method. May be generated by adding to the merge candidate block list.

According to another aspect of the present invention for achieving another object of the present invention described above, if the upper left block and the lower left second block is available to be included in the merge candidate list, the upper left block and the left If at least one of the lower second blocks is not available, the upper left second block is included in the merge candidate list in place of the unavailable block, and if both are not available, the upper left second block is substituted for the upper left block. Is included in the merge candidate list and the upper left first block and the upper right second block are included in the merge candidate list, and at least one of the upper left first block and the upper right second block is available. If not, the upper left second block is included in the merge candidate list in place of the unavailable block. It may be if it is not available, on behalf of the upper left corner of the first block comprises the step of including the steps and the temporal candidate prediction blocks to include the top left second blocks to merge candidate list to the merge candidate list. The merge candidate block list may include a fixed number of merge candidate blocks, and if the merge candidate blocks less than the fixed number are included in the merge candidate block list, additional merge candidates based on an additional merge candidate generation method. May be added to the merge candidate block list.

As described above, according to an embodiment of the present invention, a method for determining a candidate block when performing inter prediction and an apparatus using the method according to the present invention are used to merge the spatial candidate prediction blocks used when performing inter prediction and use AMVP. If used, the same can be used to reduce the complexity and improve the coding efficiency.

1 is a block diagram illustrating an image encoding apparatus according to an embodiment of the present invention.
2 is a block diagram of an image decoder according to another embodiment of the present invention.
3 is a conceptual diagram for defining a name of a spatial candidate prediction block according to another embodiment of the present invention.
4 is a conceptual diagram illustrating a method of constructing a candidate block list for inter prediction in a merge mode and an AMVP according to another embodiment of the present invention.
5 is a flowchart illustrating a method of implementing a merge candidate list according to another embodiment of the present invention.
6 is a flowchart illustrating a method of implementing an AMVP candidate list according to another embodiment of the present invention.
7 is a conceptual diagram illustrating a method of constructing a candidate block list for inter prediction in a merge mode and an AMVP according to another embodiment of the present invention.
8 is a flowchart illustrating a merge candidate list construction method according to another embodiment of the present invention.
9 is a conceptual diagram illustrating a method for constructing a candidate block list for inter prediction in a merge mode and an AMVP according to another embodiment of the present invention.
10 is a flowchart illustrating a method of implementing a merge candidate list according to another embodiment of the present invention.
11 is a conceptual diagram illustrating a method for constructing a candidate block list for inter prediction in a merge mode and an AMVP according to another embodiment of the present invention.
12 is a flowchart illustrating a method of constructing a merge candidate list for inter prediction in a merge mode according to another embodiment of the present invention.
13 is a flowchart illustrating an inter prediction method using merge and AMVP according to another embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" 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 present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Hereinafter, the same reference numerals are used for the same components in the drawings, and duplicate descriptions of the same components are omitted.

1 is a block diagram illustrating an image encoding apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the image encoding apparatus 100 may include a picture splitter 105, a predictor 110, a transformer 115, a quantizer 120, a realigner 125, and an entropy encoder 130. , An inverse quantization unit 135, an inverse transform unit 140, a filter unit 145, and a memory 150.

Each of the components shown in FIG. 1 is shown independently to represent different characteristic functions in the image encoding apparatus, and does not mean that each component is composed of separate hardware or one software configuration unit. In other words, each component is included in each component for convenience of description, and at least two of the components may be combined into one component, or one component may be divided into a plurality of components to perform a function. The integrated and separated embodiments of the components are also included in the scope of the present invention, without departing from the spirit of the invention.

In addition, some of the components are not essential components to perform essential functions in the present invention, but may be optional components only to improve performance. The present invention can be implemented only with components essential for realizing the essence of the present invention, except for the components used for the performance improvement, and can be implemented by only including the essential components except the optional components used for performance improvement Are also included in the scope of the present invention.

The picture division unit 105 can divide the inputted picture into at least one processing unit. In this case, the processing unit may be a prediction unit (PU), a transform unit (TU), or a coding unit (CU). The picture dividing unit 105 divides one picture into a plurality of coding units, a prediction unit, and a combination of conversion units, and generates a coding unit, a prediction unit, and a conversion unit combination So that the picture can be encoded.

For example, one picture may be divided into a plurality of coding units. In order to divide an encoding unit in a picture, a recursive tree structure such as a quad tree structure can be used. An encoding unit, which is divided into other encoding units with one image or a maximum-size encoding unit as a root, Can be divided by the number of child nodes. An encoding unit that is no longer divided according to certain restrictions becomes a leaf node. That is, when it is assumed that only square division is possible for one coding unit, one coding unit may be split into at most four other coding units.

Hereinafter, in the embodiment of the present invention, the meaning of a coding unit can be used not only in the unit of coding but also in the meaning of a unit of decoding.

The prediction unit may be a prediction unit having a shape of at least one square or a rectangle having the same size in one coding unit or a shape of one prediction unit among the prediction units divided in one coding unit is different from the shape of another prediction unit It can be divided into shapes.

Intra prediction can be performed without dividing into a plurality of prediction units (NxN) when a prediction unit performing intra-frame prediction based on an encoding unit is not the minimum encoding unit at the time of generation.

The prediction unit 110 may include an inter-picture prediction unit for performing inter-picture prediction and an intra-picture prediction unit for performing intra-picture prediction. It is possible to determine whether to use intra-picture prediction or intra-picture prediction for a prediction unit, and to determine concrete information (for example, intra-picture prediction mode, motion vector, reference picture, etc.) according to each prediction method. At this time, the processing unit in which the prediction is performed may be different from the processing unit in which the prediction method and the concrete contents are determined. For example, the method of prediction, the prediction mode and the like are determined as a prediction unit, and the execution of the prediction may be performed in a conversion unit. The residual value (residual block) between the generated prediction block and the original block may be input to the converter 115. In addition, the prediction mode information, motion vector information, and the like used for the prediction may be encoded by the entropy encoding unit 130 together with the residual value, and then transmitted to the decoder. When using a specific encoding mode, It is also possible to encrypt the original block as it is without generating a block and transmit it to the decoding unit

The inter picture prediction unit may predict a prediction unit based on information of at least one picture of a previous picture or a following picture of the current picture. The inter picture prediction unit may include a reference picture interpolation unit, a motion prediction unit, and a motion compensation unit.

In the reference picture interpolating unit, reference picture information is supplied from the memory 150 and pixel information of an integer pixel or less can be generated in the reference picture. In the case of a luminance pixel, a DCT-based interpolation filter having a different filter coefficient may be used to generate pixel information of an integer number of pixels or less in units of quarter pixels. In the case of a color difference signal, a DCT-based 4-tap interpolation filter having a different filter coefficient may be used to generate pixel information of an integer number of pixels or less in units of 1/8 pixel.

The motion prediction unit can perform motion prediction based on the reference picture interpolated by the reference picture interpolating unit. As a method for calculating a motion vector, various methods such as a full search-based block matching algorithm (FBMA), a three step search (TSS), and a new three-step search algorithm (NTS) may be used. The motion vector may have a motion vector value of 1/2 or 1/4 pixel unit based on the interpolated pixel. The motion prediction unit can predict the current prediction unit by differently performing the motion prediction method. As the motion prediction method, various methods such as a skip method, a merge method, and an AMVP (Advanced Motion Vector Prediction) method can be used.

The intra prediction unit can generate a prediction unit based on the reference pixel information around the current block which is the pixel information in the current picture. In the case where the neighboring blocks of the current prediction unit are the blocks in which the inter-screen prediction is performed, and the reference pixels are the pixels performing the inter-screen prediction, the intra-picture prediction is performed on the reference pixels included in the block in which the inter- Block reference pixel information. That is, when the reference pixel is not available, the reference pixel information that is not available may be replaced by at least one reference pixel among the available reference pixels.

In the intra prediction, the prediction mode may have a directional prediction mode in which reference pixel information is used according to a prediction direction, and a non-directional mode in which direction information is not used in performing prediction. The mode for predicting the luminance information may be different from the mode for predicting the chrominance information, and intra prediction mode information or predicted luminance signal information in which luminance information is predicted can be used to predict the chrominance information.

When intra prediction is performed, when the size of the prediction unit is the same as the size of the conversion unit, the intra prediction is performed based on pixels existing on the left side of the prediction unit, pixels existing on the upper left side, Prediction can be performed using the reference pixel based on the conversion unit when the size of the prediction unit and the size of the conversion unit are different when the intra prediction is performed. In addition, intra prediction using NxN division may be used only for a minimum coding unit.

In the intra prediction method, an AIS (Adaptive Intra Smoothing) filter can be applied to a reference pixel according to a prediction mode, and a prediction block can be generated. The type of the AIS filter applied to the reference pixel may be different. To perform the intra prediction method, the intra prediction mode of the current prediction unit can be predicted from the intra prediction mode of the prediction unit existing around the current prediction unit. When the prediction mode of the current prediction unit is predicted using the mode information predicted from the peripheral prediction unit and the intra prediction mode of the current prediction unit is the same as the intra prediction mode of the current prediction unit, Information indicating that the prediction mode of the neighbor prediction unit is the same can be transmitted. If the prediction mode of the current prediction unit differs from that of the neighbor prediction unit, the prediction mode information of the current block can be encoded by performing entropy encoding.

In addition, a residual block including a prediction unit that has been predicted based on the prediction unit generated by the prediction unit 110 and residual information that is a difference value between the original block of the prediction unit and the residual block may be generated. The generated residual block may be input to the conversion unit 115. The transform unit 115 converts the residual block including residual information of the original block and the prediction unit generated by the prediction unit 110 such as a discrete cosine transform (DCT) or a discrete sine transform (DST). Can be converted using Whether to apply DCT or DST to transform the residual block may be determined based on intra prediction mode information of the prediction unit used to generate the residual block.

The quantization unit 120 may quantize the values converted into the frequency domain by the conversion unit 115. [ The quantization factor may vary depending on the block or the importance of the image. The values calculated by the quantization unit 120 may be provided to the inverse quantization unit 135 and the reorder unit 125.

The reordering unit 125 may reorder the coefficient values with respect to the quantized residual values.

The reordering unit 125 may change the two-dimensional block type coefficient to a one-dimensional vector form through a coefficient scanning method. For example, the reordering unit 125 may scan from a DC coefficient to a coefficient of a high frequency region by using a Zig-Zag Scan method and change it into a one-dimensional vector. Depending on the size of the transformation unit and the intra prediction mode, the vertical scan method that scans two-dimensional block shape coefficients in the column direction rather than the zig-zag scan method, and the horizontal scan method that scans the two-dimensional block shape coefficients in the row direction Can be used. That is, it is possible to determine whether any scan method among the jig-zag scan, the vertical scan, and the horizontal scan is used according to the size of the conversion unit and the intra prediction mode.

The entropy encoding unit 130 may perform entropy encoding based on the values calculated by the reordering unit 125. For entropy encoding, various encoding methods such as Exponential Golomb, Context-Adaptive Variable Length Coding (CAVLC), and Context-Adaptive Binary Arithmetic Coding (CABAC) may be used.

The entropy encoder 130 receives residual coefficient coefficient information, block type information, prediction mode information, partition unit information, prediction unit information, transmission unit information, and motion vector information of the coding unit from the reordering unit 125 and the prediction unit 110. Various information such as reference frame information, interpolation information of a block, and filtering information may be encoded.

The entropy encoding unit 130 can entropy-encode the coefficient value of the encoding unit input from the reordering unit 125. [

In the entropy coding unit 130, a table for performing entropy coding such as a variable length coding table may be stored, and entropy coding may be performed using a stored variable length coding table. In performing entropy coding, it is possible to change a codeword allocation for a code number of a corresponding code word by using a method using a counter or a direct swapping method for a part of codewords included in a table have. For example, in a table for mapping a code number and a code word, in the case of a few upper code numbers assigned with a code word of a smaller number of bits, a code number having the largest number of code numbers It is possible to change the mapping order of the table that adaptively maps code words and code numbers so that code words can be assigned. When the counted number of times in the counter reaches a predetermined threshold value, the counter counting can be performed by dividing the counted number recorded in the counter in half.

The code number in the table that does not perform counting is a bit number assigned to the corresponding code number through the method of converting the code number and the digit directly above when the information corresponding to the code number is generated by using the direct swapping method The entropy encoding can be performed with a smaller number.

The inverse quantization unit 135 and the inverse transformation unit 140 dequantize the quantized values in the quantization unit 120 and invert the converted values in the conversion unit 115. [ The residual value generated by the inverse quantization unit 135 and the inverse transform unit 140 is combined with the prediction unit predicted through the motion estimation unit, the motion compensation unit and the intra prediction unit included in the prediction unit 110, Reconstructed Block can be created.

The filter unit 145 may include at least one of a deblocking filter, an offset correction unit, and an adaptive loop filter (ALF).

The deblocking filter 145 may remove block distortion caused by boundaries between blocks in the reconstructed picture. It may be determined whether to apply a deblocking filter to the current block based on pixels included in a few columns or rows included in the block to determine whether to perform deblocking. When a deblocking filter is applied to a block, a strong filter or a weak filter may be applied according to the deblocking filtering strength required. In applying the deblocking filter, the horizontal filtering and the vertical filtering may be performed in parallel when the vertical filtering and the horizontal filtering are performed.

The offset correction unit may correct the offset of the deblocked image with respect to the original image in units of pixels. In order to perform offset correction for a specific picture, pixels included in an image are divided into a predetermined number of areas, and then an area to be offset is determined and an offset is applied to the area. Alternatively, Can be used.

The ALF (Adaptive Loop Filter) can perform filtering based on a value obtained by comparing the filtered restored image and the original image. After dividing the pixels included in the image into a predetermined group, one filter to be applied to the group may be determined and different filtering may be performed for each group. The information related to whether to apply the ALF may be transmitted for each coding unit (CU), and the size and the coefficient of the ALF to be applied may be changed according to each block. The ALF may have various forms, and the number of coefficients included in the filter may also vary. The filtering-related information (filter coefficient information, ALF On / Off information, filter type information) of the ALF can be transmitted in a predetermined parameter set in the bitstream.

The memory 150 may store the reconstructed block or picture calculated through the filter unit 145 and the reconstructed block or picture stored therein may be provided to the predictor 110 when inter-picture prediction is performed.

2 is a block diagram of an image decoder according to another embodiment of the present invention.

2, the image decoder 200 includes an entropy decoding unit 2110, a reordering unit 215, an inverse quantization unit 220, an inverse transform unit 225, a prediction unit 230, a filter unit 235, , And a memory 240 may be included.

When an image bitstream is input in the image encoder, the input bitstream may be decoded in a procedure opposite to that of the image encoder.

The entropy decoding unit 210 can perform entropy decoding in a procedure opposite to that in which entropy encoding is performed in the entropy encoding unit of the image encoder. For example, a VLC table used for performing entropy encoding in an image coder can be implemented as an entropy decoding table in the same variable-length coding table to perform entropy decoding. Information for generating a prediction block from the information decoded by the entropy decoding unit 210 may be provided to the predicting unit 230 and residual values obtained by performing entropy decoding in the entropy decoding unit may be input to the rearranging unit 215.

The entropy decoding unit 210 may change the codeword allocation table using a counter or a direct swapping method as in the case of the entropy coding unit and may perform entropy decoding based on the changed codeword allocation table have.

The entropy decoding unit 210 can decode information related to intra-picture prediction and inter-picture prediction performed by the encoder. As described above, when there is a predetermined constraint in performing intra-frame prediction and inter-frame prediction in the image encoder, entropy decoding based on such constraints is performed to provide information related to intra-frame prediction and inter-frame prediction for the current block Can receive.

The reordering unit 215 can perform reordering based on a method in which the entropy decoding unit 210 rearranges the entropy-decoded bitstreams in the encoding unit. The coefficients represented by the one-dimensional vector form can be rearranged by restoring the coefficients of the two-dimensional block form again. The reordering unit may perform reordering by receiving information related to the coefficient scanning performed by the encoding unit and performing a reverse scanning based on the scanning order performed by the encoding unit.

The inverse quantization unit 220 can perform inverse quantization based on the quantization parameters provided by the encoder and the coefficient values of the re-arranged blocks.

The inverse transform unit 225 may perform inverse DCT and inverse DST on the DCT and DST performed by the transform unit on the quantization result performed by the image encoder. The inverse transform can be performed based on the transmission unit determined by the image encoder. In the transform unit of the image encoder, DCT and DST can be selectively performed according to a plurality of information such as a prediction method, a size and a prediction direction of a current block, and an inverse transform unit 225 of the image decoder performs transform The inverse transform can be performed based on the transformed information.

When performing a conversion, conversion can be performed based on an encoding unit rather than a conversion unit.

The prediction unit 230 may generate a prediction block based on the prediction block generation related information provided by the entropy decoding unit 210 and the previously decoded block or picture information provided in the memory 240. [

As described above, when the intra prediction is performed in the same manner as in the image encoder, when the size of the prediction unit and the size of the conversion unit are the same, pixels located on the left side of the prediction unit, pixels located on the upper left side, The intra prediction is performed on the prediction unit on the basis of the existing pixel. However, when the intra prediction is performed, when the size of the prediction unit differs from the size of the conversion unit, Prediction can be performed. In addition, intra prediction using NxN division may be used only for a minimum coding unit.

The prediction unit 230 may include a prediction unit determination unit, an inter picture prediction unit, and an intra prediction unit. The prediction unit determination unit receives various information such as prediction unit information input from the entropy decoding unit, prediction mode information of the intra prediction method, motion prediction related information of the inter picture prediction method, and separates the prediction unit from the current coding unit. Screen prediction or intra-picture prediction can be discriminated. The inter-picture prediction unit may use information necessary for inter-picture prediction of the current prediction unit provided by the image encoder to predict the current prediction unit based on information included in at least one of the previous picture of the current picture or the following picture including the current prediction unit The inter-picture prediction can be performed.

In order to perform the inter-picture prediction, whether the motion prediction method of the prediction unit included in the coding unit is based on a skip mode, a merge mode, or an AMVP mode Can be determined.

The intra prediction unit may generate a prediction block based on pixel information in the current picture. If the prediction unit is a prediction unit that performs intra prediction, the intra prediction can be performed based on the intra prediction mode information of the prediction unit provided by the image encoder. The intra-frame prediction unit may include an AIS filter, a reference pixel interpolator, and a DC filter. The AIS filter performs filtering on the reference pixels of the current block and can determine whether to apply the filter according to the prediction mode of the current prediction unit. The AIS filtering can be performed on the reference pixel of the current block using the prediction mode of the prediction unit provided in the image encoder and the AIS filter information. When the prediction mode of the current block is a mode in which AIS filtering is not performed, the AIS filter may not be applied.

When the prediction mode of the prediction unit is a prediction unit that performs intra prediction based on pixel values obtained by interpolating the reference pixels, the reference pixel interpolator may generate reference pixels having an integer value or less by interpolating the reference pixels. . The reference pixel may not be interpolated in the prediction mode in which the prediction mode of the current prediction unit generates the prediction block without interpolating the reference pixel. The DC filter can generate a prediction block through filtering when the prediction mode of the current block is the DC mode.

The restored block or picture may be provided to the filter unit 235. The filter unit 235 may include a deblocking filter, an offset correction unit, and an ALF.

When information on whether a deblocking filter is applied to a corresponding block or picture from the image encoder or a deblocking filter is applied, information on whether a strong filter or a weak filter is applied can be provided. In the deblocking filter of the video decoder, the deblocking filter related information provided by the video encoder is provided, and the video decoder can perform deblocking filtering for the corresponding block. The vertical deblocking filtering and the horizontal deblocking filtering are performed in the same manner as in the image encoder, and at least one of the vertical deblocking and the horizontal deblocking can be performed in the overlapping portion. Vertical deblocking filtering or horizontal deblocking filtering that has not been performed previously can be performed at the overlapping portions of the vertical deblocking filtering and the horizontal deblocking filtering. Parallel processing of deblocking filtering is possible through the deblocking filtering process.

The offset correction unit may perform offset correction on the reconstructed image based on the type of offset correction applied to the image and the offset value information during encoding.

The ALF can perform filtering based on the comparison between the reconstructed image and the original image after filtering. The ALF can be applied to the encoding unit based on the ALF application information and the ALF coefficient information provided from the encoder. Such ALF information may be provided in a specific parameter set.

The memory 240 may store the reconstructed picture or block to use as a reference picture or reference block, and may provide the reconstructed picture to the output unit.

As described above, in the embodiment of the present invention, a coding unit is used as a coding unit for convenience of description, but may also be a unit for performing decoding as well as encoding. Hereinafter, an encoding / decoding method of an intra prediction mode using the two candidate intra prediction modes described with reference to FIGS. 3 to 8 according to an embodiment of the present invention is implemented according to the functions of the respective modules described above with reference to FIGS. 1 and 2. And such an encoder and a decoder are included in the scope of the present invention.

3 is a conceptual diagram for defining a name of a spatial candidate prediction block according to another embodiment of the present invention.

(X, y), the width of the current prediction unit is defined as nPSW, and the width is defined as a variable called nPSH. MinPuSize, a variable for representing a spatial candidate prediction unit, indicates the size of the smallest prediction unit that can be used in the prediction unit.

Hereinafter, in the exemplary embodiment of the present invention, the block including the pixel existing at the position (x-1, y) is the upper left block 300, and the block including the pixel present at the position (x, y-1) is the uppermost. A block including a pixel existing at a left first block 310 and a (x-MinPuSize, y-1) position is defined as a term of the upper left second block 320.

Also, the block including the pixel existing at the position (x + nPSW-MinPuSize, y-1) includes the pixel existing at the position of the upper right first block 330 and the (x + nPW + 1, y-1) position. The block to be defined is defined as a term of the upper right second block 340, and a block including a pixel existing at a position (x-1, y + nPSH-MinPuSize) is defined as a lower left first block 350 and (x-1). , a block including a pixel present at a position of y + nPSH) is defined as a term of a lower left second block 360.

4 is a conceptual diagram illustrating a method of constructing a candidate block list for inter prediction in a merge mode and an AMVP according to another embodiment of the present invention.

Referring to FIG. 4, in the merge mode, the candidate block list is the first lower left second block 400, the second upper right second block 410, and the third lower left first when assuming that all blocks are available. Block 420, fourth upper right first block 430, fifth upper left second block 440, and sixth temporal candidate prediction block 450.

In implementing the merge candidate block list, a merge candidate having the same motion information may be excluded from the merge candidate block list except only the merge candidate having the highest priority.

The merge candidates included in the merge candidate block list may have a fixed number. For example, the merge candidate block list may have five merge candidates fixedly. In addition, in having 5 merge candidates, the number of spatial candidate prediction blocks may be limited to a certain number. For example, if it is possible for the merge candidate list to include four spatial candidate prediction blocks, the bottom left second block 400, the top right second block 410, the bottom left first block 420, and the top If there are blocks that are not available among the right first blocks 430, the upper left second block 440, which is fifth in the order of priority, may replace blocks that are not available in the merge candidate list.

In the case of using AMVP, the availability of the blocks is determined in the order of the lower left second block 400 from the lower left first block 420 to use the motion vector of the first available block as the candidate prediction motion vector. Next, the motion vector of the first block available is determined by determining whether the blocks are available in the order of the upper right second block 410, the upper right first block 430, and the upper left second block 440. Finally, the motion vector of the temporal candidate prediction block may be used as the candidate prediction motion vector. The calculated candidate prediction motion vectors may be included in the candidate prediction motion vector list, and when there are three candidate prediction motion vectors, only two candidate prediction motion vectors may be used.

5 is a flowchart illustrating a method of implementing a merge candidate list according to another embodiment of the present invention.

If the lower left second block is available, the lower left second block is inserted into the merge candidate list (step S500).

If the upper right second block is available, the upper right second block is inserted into the merge candidate list (step S510).

If the lower left first block is available, the lower left first block is inserted into the merge candidate list (step S520).

If the upper right first block is available, the upper right first block is inserted into the merge candidate list (step S530).

If the upper left second block is available, the upper left second block is inserted into the merge candidate list (step S540).

If the temporal candidate prediction block h is available, the temporal candidate prediction block h is inserted into the merge candidate list (step S550).

After the merge candidate block list is configured through the above procedure, when all six merge candidates are available, the merge candidate list may be generated by selecting only five merge candidates sequentially. In the merge candidate list, when a plurality of merge candidates have the same motion information (motion vector, reference picture index, etc.), only the merge candidate with the highest priority is left in the merge candidate block list, and the remaining same merge candidate is It can be deleted from the merge candidate block list.

If a list having a certain number of merge candidates is not generated through the merge candidate list generation process described above with reference to FIG. 5, the merge candidate list may be generated by performing an additional merge candidate generation process.

For example, the combined merge candidate generation method may generate a merge candidate having new motion information by combining motion information of the merge candidate included in the existing merge candidate list. If motion information in one direction included in the merge candidate list is called first motion information and motion information in another direction is called second motion information, new motion information may be generated by combining the first motion information and the second motion information. The generated new motion information may be included in the merge candidate list as the merge candidate. Hereinafter, in the embodiment of the present invention, such merge information generation method is referred to as a combined merge candidate generation method.

The scaling merge candidate generation method may generate a new motion vector by reversing the direction of an existing motion vector. For example, when a vector having a value A as the first merge candidate exists in the merge candidate list, the second merge candidate having a negative value A vector may be included in the merge candidate list. In this case, the reference picture pointed by the negative vector A refers to a reference picture having the same picture interval in the opposite direction based on the picture gap information related to the reference picture pointed to by the existing A vector on the reference picture list. You can decide. When the distance between the reference picture indicated by the A vector and the reference picture indicated by the negative A vector is different based on the current picture, the vector value may be changed through scaling. If the complexity is to be implemented in a low complexity manner, the scaling merge candidate generation method is generated only when a negative value A vector has the same distance between the current picture and the reference picture in the opposite direction, that is, no scaling is performed. Merge candidates may be included in the merge candidate list.

In addition, a new merge candidate list may be generated by replacing a value of a motion vector with a zero vector in an existing merge candidate list. This merge information generation method is called a zero vector merge candidate generation method.

When the merge candidate list included in the merge candidate list is not completely filled through the process of constructing the merge candidate list using the spatial candidate prediction block and the temporal candidate prediction block described above with reference to FIG. Merge candidates to be included may be generated.

6 is a flowchart illustrating a method of implementing an AMVP candidate list according to another embodiment of the present invention.

A motion vector calculated from the first available block determined based on the order of the lower left first blocks in the lower left second block is calculated as the candidate prediction motion vector (step S600).

The motion vector calculated in the first block determined based on the order of the upper right second block, the upper right first block, and the upper left second block is calculated as the candidate prediction motion vector (step S610).

If the temporal prediction candidate block is available, the motion vector calculated from the temporal prediction candidate block is calculated as the candidate prediction motion vector (step S620).

In operation S600, the candidate prediction motion vector calculated through step S620 may be included in the candidate prediction motion vector list. When the same sized vector exists among the calculated candidate prediction motion vectors, the remaining candidate prediction motion vectors may be removed from the candidate prediction motion vector list except only the candidate prediction motion vectors having high priority. As described above, if two fixed numbers of candidate prediction motion vectors are used in the candidate prediction motion vector list. If three candidate prediction motion vectors exist in the candidate prediction motion vector list, only two candidate prediction motion vectors may be used in order of priority. If the number of candidate motion vectors is less than two, a method of adding zero vectors may be used. Can be used to implement a candidate predicted motion vector list.

7 is a conceptual diagram illustrating a method of constructing a candidate block list for inter prediction in a merge mode and an AMVP according to another embodiment of the present invention.

Referring to FIG. 7, in order to construct a merge candidate list, first, an upper left block 700, a second upper left first block 710, a third upper right second block 720, and a fourth lower left first The merge candidate block list may be constructed using the second block 730, the fifth upper left second block 740, and the sixth temporal candidate prediction block 750.

When implementing the merge candidate block list, the priority of the fifth upper left second block 740 of the list and the sixth temporal candidate prediction block 750 of the list is changed to be the first upper left block 700 and the second. Upper left first block 710, third upper right second block 720, fourth lower left second block 730, fifth temporal candidate prediction block 750, sixth upper left first The merge candidate block list may be constructed using the two blocks 740.

As described above, the merge candidate block list may have a fixed number. For example, five merge candidates may be included in the merge candidate block list, and in the case of five merge candidates, the number of spatial candidate prediction blocks may be limited to a certain number.

In addition, the merge candidate block having the same motion information may be excluded leaving only the merge candidate having the highest priority in the merge candidate block list. In addition, when a merge candidate block list having a predetermined number of merge candidates is used, the merge candidates may be included in the merge candidate block list through the above-described additional merge candidate generation process.

Similarly, when a certain number of merge candidate blocks do not exist in the merge candidate block list, the merge candidate blocks may be merge candidates through the combined merge candidate generation method, the scaling merge candidate generation method, and the zero vector merge candidate generation method described above. Can be included in the block list.

In the case of AMVP, in selecting one block from the top, in the above-described FIGS. 4 and 5 except that the availability of the block is determined in the order of the upper right second block, the upper left first block, and the upper left second block. The predictive motion vector of the current prediction unit may be calculated by calculating the candidate prediction vector in the same manner as described above.

8 is a flowchart illustrating a merge candidate list construction method according to another embodiment of the present invention.

Referring to FIG. 8, when the upper left block is available, the upper left block is included in the merge candidate list (step S800).

If the upper left first block is available, the upper left first block is included in the merge candidate list (step S810).

If the upper right second block is available, the upper right second block is included in the merge candidate list (step S820).

If the lower left second block is available, the lower left second block is included in the merge candidate list (step S830).

If the upper left second block is available, the upper left second block is included in the merge candidate list (step S840).

If the temporal candidate prediction block is available, the temporal candidate prediction block is included in the merge candidate list (step S850).

As described above, after configuring the merge candidate list through the above procedure, if all six are available, the merge candidate list may be generated by selecting only five merge candidates sequentially. In the merge candidate list, if a plurality of merge candidates have the same motion information (motion vector, reference picture index, etc.), only the highest priority merge candidate is left in the merge candidate list, and the remaining same merge candidate is merged. You can delete it from the list. When the number of merge candidates is insufficient in the merge candidate list, the merge candidate may be additionally included in the merge candidate list through the aforementioned additional merge candidate generation method.

9 is a conceptual diagram illustrating a method for constructing a candidate block list for inter prediction in a merge mode and an AMVP according to another embodiment of the present invention.

Referring to FIG. 9, first, the left lower first block 900 and the second lower left second block 910 are selected. If one of the lower left first block 900 and the lower left second block 910 is not available, the unavailable block may be replaced with the upper left second block 940. If neither the lower left first block 900 nor the lower left second block 910 is available, the upper left second block 940 may be replaced with the lower left first block 900.

Next, the first upper right first block 920 and the second upper right second block 930 are selected first. If one of the upper right first block 920 and the upper right second block 930 is not available, the unavailable block may be replaced with the upper left second block 940. If the upper right first block 920 and the upper right second block 930 are not available, the upper left first block 940 may be replaced with the upper right first block 920. The temporal candidate prediction block 950 may always be included in the merge candidate list when available. Likewise, in the merge candidate list, if a plurality of merge candidates have the same motion information (motion vector, reference picture index, etc.) in FIG. 9, only the merge candidate with the highest priority is left in the merge candidate list and the remaining same merge candidate Can be deleted from the merge list. When the number of merge candidates is insufficient in the merge candidate list, the merge candidate may be additionally included in the merge candidate list through the aforementioned additional merge candidate generation method.

In the AMVP, the prediction vector of the current prediction unit may be calculated by calculating the candidate prediction vector in the same manner as described above with reference to FIGS. 4 and 5.

10 is a flowchart illustrating a method of implementing a merge candidate list according to another embodiment of the present invention.

Referring to FIG. 10, if the lower left first block and the lower left second block are available, they are included in the merge candidate list, and if at least one of the lower left first block and the lower left second block is not available, they are not available. The upper left second block is included in the merge candidate list instead of the unblocked block, and if both are not available, the upper left second block is included in the merge candidate list instead of the lower left first block (step S1000).

If the upper right first block and the upper right second block are available, they are included in the merge candidate list, and if at least one of the upper right first block and the upper right second block is not available, the upper part replaces the unavailable block. If the left second block is included in the merge candidate list and neither is available, the upper left second block is included in the merge candidate list instead of the lower left first block (step S1010).

The temporal candidate prediction block is included in the merge candidate list (step S1020).

In implementing the merge candidate list, if a plurality of merge candidates have the same motion information (motion vector, reference picture index, etc.), only the highest priority merge candidate is left in the merge candidate list, and the remaining identical merge candidates are included in the merge list. You can delete it. When the number of merge candidates is insufficient in the merge candidate list, the merge candidate may be additionally included in the merge candidate list through the aforementioned additional merge candidate generation method.

11 is a conceptual diagram illustrating a method for constructing a candidate block list for inter prediction in a merge mode and an AMVP according to another embodiment of the present invention.

Referring to FIG. 11, first, an upper left block 1100 and a second lower left second block 1110 are first selected. If the upper left block 1100 and the lower left second block 1110 are not available, the unavailable block may be replaced with the upper left second block 1120. When neither the upper left block 1100 and the lower left second block 1110 are available, the upper left second block 1120 may replace the upper left block 1100.

Next, the first upper left first block 1130 and the second upper right second block 1140 are selected first. If the upper left first block 1130 and the upper right second block 1140 are not available, the unavailable block may be replaced with the upper left second block 1120. When neither the upper left first block 1130 nor the upper right second block 1140 is available, the upper left second block 1120 may replace the upper left first block 1130. The temporal candidate prediction block 1150 may always be included in the merge candidate list when available.

In implementing the merge candidate list, if a plurality of merge candidates have the same motion information (motion vector, reference picture index, etc.), only the highest priority merge candidate is left in the merge candidate list, and the remaining identical merge candidates are included in the merge list. You can delete it. When the number of merge candidates is insufficient in the merge candidate list, the merge candidate may be additionally included in the merge candidate list through the aforementioned additional merge candidate generation method.

In the case of AMVP, in selecting one block from the top, in the above-described FIGS. 4 and 5 except that the availability of the block is determined in the order of the upper right second block, the upper left first block, and the upper left second block. The predictive motion vector of the current prediction unit may be calculated by calculating the candidate prediction vector in the same manner as described above.

12 is a flowchart illustrating a method of constructing a merge candidate list for inter prediction in a merge mode according to another embodiment of the present invention.

Referring to FIG. 12, when an upper left block and a lower left second block are available to form a merge candidate list, the merge candidate list is included in the merge candidate list, and at least one of the upper left block and the lower left second block is not available. If the upper left second block is included in the merge candidate list instead of the unavailable block, and if neither is available, the upper left second block is included in the merge candidate list instead of the upper left block (step S1200).

If the upper left first block and the upper right second block are available, they are included in the merge candidate list, and if at least one of the upper left first block and the upper right second block is not available, the upper part replaces the unavailable block. If the left second block is included in the merge candidate list and neither is available, the upper left second block is included in the merge candidate list instead of the upper left first block (step S1210).

If the temporal candidate prediction block is available, it is included in the merge candidate list (step S1220).

13 is a flowchart illustrating an inter prediction method using merge and AMVP according to another embodiment of the present invention.

Referring to FIG. 13, it is determined whether a current prediction unit is predicted between screens using merge (step S1300).

Whether the inter prediction method using merge as the current prediction unit is used may be calculated based on merge flag information.

If the current prediction unit is predicted between the screens using merge, a merge candidate list is generated (step S1310).

As the method for generating the merge candidate list, one of the methods of FIG. 4 to FIG. 13 described above may be used.

A prediction block is generated in the current prediction unit based on the index information of the merge candidate list used in the current prediction unit (step S1320).

Based on the merge candidate index information transmitted from the encoder, it is determined whether motion prediction information of which block is used in the merge candidate list and generates a prediction block of the current prediction unit based on the motion prediction information of the corresponding block.

If the current prediction unit is predicted between screens using AMVP, an AMVP candidate list is generated (step S1330).

As the method of generating the AMVP candidate list, one of the methods of FIG. 4 to FIG. 13 described above may be used.

A prediction block is generated in the current prediction unit based on the index information of the AMVP candidate list used in the current prediction unit (step S1340).

Based on the index information of the AMVP candidate list transmitted from the encoder, it is determined whether motion prediction information of which block is used in the AMVP candidate list generated and generates a prediction block of the current prediction unit based on the motion prediction information of the corresponding block. .

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. It will be possible.

Claims (19)

If the lower left second block is available, including the lower left second block in a merge candidate list;
If the upper right second block is available, including the upper right second block in the merge candidate list;
If the lower left first block is available, including the lower left first block in the merge candidate list;
If the upper right first block is available, including the upper right first block in the merge candidate list;
If the upper left second block is available, including the upper left second block in the merge candidate list; And
And if the temporal candidate prediction block is available, including the temporal candidate prediction block in the merge candidate block list. The apparatus of claim 1, wherein the merged candidate block list includes:
If the merge candidate block may include a fixed number of merge candidate blocks and the fixed number of merge candidate blocks is included in the merge candidate block list, only a fixed number of merge candidate blocks may be included in the merge candidate block list based on priority. Image decoding method comprising. The apparatus of claim 1, wherein the merged candidate block list includes:
If the merge candidate block may include a fixed number of merge candidate blocks and less than the fixed number of merge candidate blocks is included in the merge candidate block list, the merge candidate block list may be further merged based on an additional merge candidate generation method. Video decoding method to add to. The method of claim 3, wherein the additional merge candidate generation method,
And at least one of a combined merge candidate generation method, a scaling merge candidate generation method, and a zero vector merge candidate generation method. Calculating a motion vector calculated from the first available block determined based on the order of the lower left first blocks in the lower left second block as a candidate prediction motion vector;
Calculating a motion vector calculated from the first block determined based on the order of the upper right second block, the upper right first block, and the upper left second block as a candidate prediction motion vector;
If a temporal prediction candidate block is available, calculating a motion vector calculated from the temporal prediction candidate block as a candidate prediction motion vector; And
And constructing an AMVP list using the calculated candidate prediction motion vectors. The method of claim 5, wherein the AMVP list,
When the fixed number of candidate prediction motion vectors may be included in the AMVP list, the fixed number of candidate prediction motion vectors may be included in the AMVP list. The video decoding method. The method of claim 5, wherein the AMVP list,
And a zero vector as a candidate prediction motion vector in the AMVP list when the AMVP list includes a fixed number of candidate prediction motion vectors and less than the fixed number of candidate prediction motion vectors is included in the AMVP list. If the upper left block is available, including the upper left block in a merge candidate list;
If the upper left first block is available, including the upper left first block in a merge candidate list;
If the upper right second block is available, including the upper right second block in a merge candidate list;
If the lower left second block is available, including the lower left second block in a merge candidate list;
If the upper left second block is available, including the upper left second block in a merge candidate list; And
And if the temporal candidate prediction block is available, including the temporal candidate prediction block in a merge candidate list. The method of claim 8, wherein the merge candidate block list,
If the merge candidate block may include a fixed number of merge candidate blocks and the fixed number of merge candidate blocks is included in the merge candidate block list, only a fixed number of merge candidate blocks may be included in the merge candidate block list based on priority. Image decoding method comprising. The method of claim 8, wherein the merge candidate block list,
If the merge candidate block may include a fixed number of merge candidate blocks and less than the fixed number of merge candidate blocks is included in the merge candidate block list, the merge candidate block list may be further merged based on an additional merge candidate generation method. Video decoding method to add to. The method of claim 10, wherein the additional merge candidate generation method,
And at least one of a combined merge candidate generation method, a scaling merge candidate generation method, and a zero vector merge candidate generation method. Calculating a motion vector calculated from the first available block determined based on the order of the lower left first blocks in the lower left second block as a candidate prediction motion vector;
Calculating a motion vector calculated from the first block determined based on the order of the upper right second block, the upper left first block, and the upper left second block as a candidate prediction motion vector;
If a temporal prediction candidate block is available, calculating a motion vector calculated from the temporal prediction candidate block as a candidate prediction motion vector; And
And constructing an AMVP list using the calculated candidate prediction motion vectors. The method of claim 12, wherein the AMVP list,
When the fixed number of candidate prediction motion vectors may be included in the AMVP list, the fixed number of candidate prediction motion vectors may be included in the AMVP list. The video decoding method. The method of claim 12, wherein the AMVP list,
And a zero vector as a candidate prediction motion vector in the AMVP list when the AMVP list includes a fixed number of candidate prediction motion vectors and less than the fixed number of candidate prediction motion vectors is included in the AMVP list. If the lower left first block and the lower left second block are available, they are included in the merge candidate list. If at least one of the lower left first block and the lower left second block is not available, the block is not available. Including the upper left second block in the merge candidate list in place of the lower left first block if the upper left second block is included in the merge candidate list and neither is available; And
If the upper right first block and the upper right second block are available, they are included in the merge candidate list. If at least one of the upper right first block and the upper right second block is not available, the unavailable block is included. Instead including the upper left second block in the merge candidate list and if both are not available, including the upper left second block in the merge candidate list in place of the lower left first block; And
And including the temporal candidate prediction block in the merge candidate list. If the lower left first block and the lower left second block are available, they are included in the merge candidate list. If at least one of the lower left first block and the lower left second block is not available, the block is not available. Including the upper left second block in the merge candidate list in place of the lower left first block if the upper left second block is included in the merge candidate list and neither is available; And
If the upper right first block and the upper right second block are available, they are included in the merge candidate list. If at least one of the upper right first block and the upper right second block is not available, the unavailable block is included. Instead including the upper left second block in the merge candidate list and if both are not available, including the upper left second block in the merge candidate list in place of the lower left first block; And
And including the temporal candidate prediction block in the merge candidate list. The method of claim 16, wherein the merge candidate block list,
If the merge candidate block may include a fixed number of merge candidate blocks and less than the fixed number of merge candidate blocks is included in the merge candidate block list, the merge candidate block list may be further merged based on an additional merge candidate generation method. Video decoding method to add to. If the upper left block and the lower left second block are available, they are included in the merge candidate list, and if at least one of the upper left block and the lower left second block is not available, the upper left second is substituted for the unavailable block. If the block is included in the merge candidate list and neither is available, including the upper left second block in the merge candidate list in place of the upper left block; And
If the upper left first block and the upper right second block are available, they are included in the merge candidate list. If at least one of the upper left first block and the upper right second block is not available, the unavailable block is included. Instead including the upper left second block in the merge candidate list and if both are not available, including the upper left second block in the merge candidate list in place of the upper left first block; And
And including the temporal candidate prediction block in the merge candidate list. The method of claim 18, wherein the merge candidate block list,
If the merge candidate block may include a fixed number of merge candidate blocks and less than the fixed number of merge candidate blocks is included in the merge candidate block list, the merge candidate block list may be further merged based on an additional merge candidate generation method. Video decoding method to add to.

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