Abstract: A method of video processing is described. The method includes: deriving, for a conversion between a current block of a video and a coded representation of the video, a prediction block for the current block that is determined according to a tool in which weights are used to determine a weighted sum of two initial prediction blocks used to determine the prediction block; and performing the conversion using the prediction block; wherein the deriving includes: applying the weights to two intermediate prediction samples that respectively belong to the two initial prediction blocks to derive a final prediction sample; and performing a right shift operation for the final prediction sample, wherein the right shift operation is pbSample>> (shift1+3)), wherein pbSample represents the final prediction sample, shift1 is set equal to Max(2, 14?bitDepth); and determining the prediction block based on the final prediction sample.

Abstract: An image encoding/decoding method and apparatus are provided. An image decoding method performed by an image decoding apparatus may comprise identifying a current chroma block by splitting an image, identifying whether a matrix based intra prediction mode applies to a first luma sample position corresponding to the current chroma block, identifying whether a predetermined prediction mode applies to a second luma sample position corresponding to the current chroma block, based on the matrix based intra prediction mode doing not apply, and determining an intra prediction mode candidate of the current chroma block based on an intra prediction mode applying to a third luma sample position corresponding to the current chroma block, based on the predetermined prediction mode doing not apply.

Abstract: Provided is a picture encoding device that divides a picture into blocks and performs encoding for each of the divided blocks. A primary signal block divider divides a primary signal of the picture into rectangles having a predetermined size, and generates a primary signal block. A secondary signal block divider divides a secondary signal of the picture into rectangles having a predetermined size, and generates a secondary signal block. A primary signal predictor predicts a primary signal, and a secondary signal predictor predicts a secondary signal. The secondary signal predictor can perform inter prediction of predicting a secondary signal from an encoded primary signal, and the inter prediction is restricted based on at least one of a size of the primary signal block and a size of the secondary signal block.

Abstract: An object of the embodiments is to achieve an improved reference picture handling. That is achieved by taking into account whether the reference pictures in the decoded picture buffer are long-term reference pictures or short-term reference pictures when determining how they should be marked when the information of the reference picture set is received. The reference pictures are marked as “used for short-term reference” or “used for long-term reference” in the Decoded Picture Buffer (DPB) depending on whether they are included as short-term pictures or long-term pictures in the RPS of a current picture.

Abstract: Methods, systems and apparatus for video processing are described. One example video processing method includes performing a conversion between a video including a video block and a bitstream of the video according to a rule, wherein the rule specifies whether to include, in a slice header (SH), a first syntax element that indicates whether a transform skip based residual coding is disabled for a slice, and wherein the rule specifies that whether to include the first syntax element in the SH is selectively based on a second syntax element in a sequence parameter set (SPS) that indicates whether a TS mode is enabled for the video block.

Abstract: A method of decoding a coded video bitstream includes obtaining a sequence parameter set (SPS)-level syntax element from the bitstream, wherein that the SPS-level syntax element equaling a preset value specifies that no video parameter set (VPS) is referred to by a SPS, and wherein the SPS-level syntax element being greater than the preset value specifies that the SPS refers to a VPS. The method further includes obtaining, when the SPS-level syntax element is greater than the preset value, an inter-layer enabled syntax element specifying whether one or more inter-layer reference pictures (ILRPs) are enabled to be used for the inter prediction of one or more coded pictures, and predicting one or more coded pictures based on the value of the inter-layer enabled syntax element.

Abstract: In an exemplary aspect, a method for visual media processing includes identifying a boundary at a vertical edge and/or a horizontal edge of two video blocks; calculating a boundary strength of a filter based on at least one of the two video blocks crossing a vertical edge or a horizontal edge is coded using a combined intra-inter prediction (CIIP) mode; deciding whether to turn on or off the filter; selecting a strength of the filter in case the filter is turned on; and performing, based on the selecting, a deblocking filter (DB) process to the video blocks.

Abstract: Video codec concepts which allows more effective video composition/merging and/or a more effective implementation of gradual decoding refresh are described along with concepts of allowing video composition/merging being more effective, for instance, in terms of complexity of the composition/merging task.

Abstract: The present technique relates to an image processing device and method which can suppress an increase in an operation time. The image processing device has: an encoding control unit which, upon encoding independently performed per slice for dividing a picture into a plurality of pictures, controls whether or not to adopt for motion information a merge mode of merging a relevant region of an operation target with a surrounding region positioned in a surrounding of the relevant region, based on information of surrounding regions which belong to a relevant slice to which the relevant region belongs; and an encoding unit which encodes the relevant region in the merge mode or a mode other than the merge mode under control of the encoding control unit. The present disclosure is applicable to the image processing device.

Abstract: A video decoding method includes predicting a current block according to an intra prediction mode of the current block, determining whether to apply position dependent intra prediction filtering to the current block according to the intra prediction mode of the current block, when the position dependent intra prediction filtering is applied to the current block, determining at least one of an upper reference sample, a left reference sample, an upper weight, and a left weight for the position dependent intra prediction filtering of a current sample of the current block according to the intra prediction mode of the current block, and applying the position dependent intra prediction filtering to the current sample of the current block according to at least one of the upper reference sample, the left reference sample, the upper weight, and the left weight.

Abstract: A multi-stage coding method includes receiving an input block of data for encoding and one or more previously coded samples associated with the input block. The input block is segmented into at least a first sub-region and a second sub-region. A prediction for the first sub-region is generated based on the one or more previously coded samples. Residual data for the first sub-region is obtained using the prediction for the first sub-region. A reconstruction of the first sub-region is generated using the residual data for the first sub-region and the prediction for the first sub-region. A prediction for the second sub-region is generated using the reconstruction of the first sub-region. Residual data for the second sub-region is obtained using the prediction for the second sub-region. The input block is encoded based in part on the residual data for the first region and the residual data for the second region.

Abstract: The present disclosure provides a chroma block prediction method and a device. The method includes: parsing a bitstream to obtain first indication information; downsampling a first luma block by a first filter when a value of the first indication information is a first value or by using a second filter when a value of the first indication information is a second value, to obtain a second luma block; obtaining a plurality of chroma samples and a plurality of luma samples; obtaining linear model coefficients based on the plurality of chroma samples and the plurality of luma samples; and obtaining a prediction value of the current chroma block based on the second luma block and the linear model coefficients.

Abstract: An image decoding apparatus includes: a first filter unit configured to apply a first filter to an image (a luminance image and a chrominance image); a second filter unit configured to apply a second filter to an output image of the first filter; a filter set derivation unit configured to decode a filter coefficient from coded data; and a third filter unit configured to apply a third filter to an output image of the second filter by using the filter coefficient. In a case that the third filter unit performs filter processing for the luminance image by using a luminance output image of the second filter, the third filter unit performs processing of clipping an amount of change of a pixel value through the filter processing within a prescribed range of value.

Abstract: An encoding method for a picture part encoded in a bitstream and reconstructed can involve refinement data encoded in the bitstream and determined based on at least one comparison of a version of a rate distortion cost computed using a data coding cost, a distortion between an original version of the picture part and a reconstructed picture part, and at least one other version involving one or more combinations of with or without a refinement by the refinement data, or a refinement either in or out of the decoding loop, or with or without a mapping or an inverse mapping.

Abstract: Different implementations are described, particularly implementations for video encoding and decoding based on asymmetric binary partitioning of image blocks are presented. The encoding method comprises for a picture, wherein at least one component of the picture is divided into blocks of samples, partitioning a block into block partitions, wherein at least one block partition has a size equal to a positive integer different from a power of 2 in width and/or height, obtaining a residual based on a difference between a prediction of the block partitions and the block partitions, splitting the residual into at least two residual blocks with a size equal to a power of 2 in width and height and encoding the at least two residual blocks. Ohers embodiments are presented for a block partitioning on the border of the picture, for setting maximum and/or minimum block sizes and for corresponding decoding method.

Abstract: Block-based coding of a picture is rendered more effective by providing an intra-prediction coding concept according to which a certain block of the picture is intra-prediction coded using a certain intra-coding mode by partitioning the predetermined block into partitions along a certain dimension with the number of partitions being greater than two and/or the partitions being one sample wide along the certain dimension with the partitions being, for reconstruction purposes, sequentially subject to spatial prediction using the intra-prediction coding mode signaled for the certain block followed by correcting the thus obtained predictor using a prediction residual so that for preceding partitions a reconstruction of the samples is available to the decoder at the time of processing the next, then current, partition. Signaling overhead with respect to the partitioning may be left off or may be kept low.

Abstract: Methods and systems are provided for decoding at least one video stream. A method includes receiving a first network abstraction layer (NAL) unit of a first slice of a coded picture and a second VCL NAL unit of a second slice of the coded picture, the first VCL NAL unit having a first VCL NAL unit type and the second VCL NAL unit having a second VCL NAL unit type that is different from the first VCL NAL unit type, and decoding the coded picture, the decoding including determining a picture type of the coded picture based on the first VCL NAL unit type of the first VCL NAL unit and the second VCL NAL unit type of the second VCL NAL unit, or based on an indicator, received by the at least one processor, indicating that the coded picture includes mixed VCL NAL unit types.

Abstract: An image coding method includes: writing, into a sequence parameter set, buffer description defining information for defining a plurality of buffer descriptions; writing, into the sequence parameter set, reference list description defining information for defining a plurality of reference list descriptions corresponding to the buffer descriptions; and writing, into a first header of each processing unit which is included in a coded bitstream, buffer description selecting information for specifying a selected buffer description.

Abstract: A method and apparatus of video coding, where according to one method, input data related to a current block in a current picture are received at a video encoder side or compressed data comprising the current block are received at a video decoder side. A first syntax at a high level in a video bitstream regarding residual coding type is signaled at the encoder side or parsed at the decoder side. A target coding mode is determined for the current block based on information comprising a value of the first syntax. The current block is encoded at the encoder side or decoded at the decoder side according to the target coding mode. The high level may correspond to a slice header or a picture header.

Abstract: A data decoding method, performed by a computer device, is provided. The data decoding method includes obtaining coded data corresponding to a current to-be-decoded unit, obtaining a coding mode restriction type corresponding to the current to-be-decoded unit by decoding the coded data, determining a candidate coding mode set corresponding to the current to-be-decoded unit according to the coding mode restriction type, the candidate coding mode set comprising a block copy intra-frame coding mode, selecting a target coding mode from the candidate coding mode set, and decoding the current to-be-decoded unit according to the target coding mode, thereby obtaining corresponding decoded data.

Abstract: An apparatus for video decoding includes receiving and processing circuitry. The circuitry is configured to receive a bitstream including a syntax element associated with a parent coding unit (CU) in a picture indicating the parent CU is partitioned into a predefined set of child CUs without performing a recursive tree-structure-based partitioning, and process the child CUs according to the indication of the syntax element to reconstruct the picture. In an embodiment, at least two subdivisions need to be performed when the parent CU is partitioned using the recursive tree-structure-based partitioning in order to obtain the same set of child CUs. In an embodiment, at least one of the child CUs has a size larger than a minimum allowed CU size for partitioning the parent CU and includes no syntax element to indicate whether the at least one of the child CUs is to be further subdivided.

Abstract: A method of controlling intra prediction for decoding or encoding of a video sequence, is performed by at least one processor and includes obtaining intra prediction modes including directional modes respectively corresponding to angular prediction directions, a first amount of one or more of the directional modes being excluded from the intra prediction modes based on a second amount of the intra prediction modes and a third amount of most probable modes (MPMs). The method further includes selecting, as the MPMs, two or more of the intra prediction modes from which the one or more of the directional modes are excluded, and selecting, for decoding the video sequence, one of the intra prediction modes from which the one or more of the directional modes are excluded.

Abstract: A transmission apparatus, a transmission method, and a program that can reduce the number of times that useless transmission of image data is performed due to a failure in reception of image data indicating a reference destination. A transmission failure likelihood data management section checks the likelihood of a failure in transmission of first image data. Second image is an image rendered in a frame buffer for the first time after a timing when a predetermined time has elapsed since the transmission of the first image data. An encoding processing section controls whether or not to generate second image data requiring no reference destination, depending on the likelihood of the failure in the transmission of the first image data at a timing of encoding the second image.

Abstract: A method for decoding an image by a decoding apparatus according to the present invention comprises the steps of: deriving predicted samples by performing prediction on a current block; determining whether the current block is to be divided, on the basis of a size and a maximum transform size of the current block; when the current block is determined to be divided, dividing the current block into transform blocks; deriving transform coefficients of the transform blocks; deriving residual samples by performing an inverse transform procedure for the transform coefficients; and generating a reconstructed picture on the basis of the residual samples and the predicted samples, wherein, when the size of the current block is larger than the maximum transform size, the current block is determined to be divided.

Abstract: A method of decoding a coded video bitstream is provided. The method includes receiving a bitstream containing an external decoder refresh (EDR) picture and a list of pictures for the EDR picture. The list of pictures lists pictures referred to by entries in a first reference picture list, pictures referred to by entries in a second reference picture list, and external pictures in increasing decoding order. A difference between picture order count values for any two consecutive pictures in the list of pictures is greater than one half of a negative of maximum picture order count least significant bits and less than one half of the maximum picture order count least significant bits. The method further includes obtaining an external picture from the the external pictures referred to in the list of pictures and decoding the EDR picture using the external picture that was obtained.

Abstract: An example device for coding video data includes memory configured to store the video data and one or more processors implemented in circuitry and communicatively coupled to the memory. The one or more processors are configured to determine whether a sequence parameter set of the video data refers to a video parameter set. Based on the sequence parameter set not referring to the video parameter set, the one or more processors are configured to determine a value of a first syntax element to be indicative of a profile-tier-layer structure being signaled in the sequence parameter set and code the video data based on the profile-tier-layer structure.

Abstract: Aspects of the disclosure provide method and apparatus for video coding. In some examples, an apparatus includes receiving circuitry and processing circuitry. The processing circuitry selects a reference line from a plurality of potential reference lines and selects an intra prediction mode from a set of potential intra prediction modes that is associated with the reference line. The processing circuitry encodes a block according to the intra prediction mode and at least one reference sample in the reference line. The processing circuitry further generates prediction information of the block. Inclusion of an indication of a reference line index of the reference line in the prediction information is based on the intra prediction mode.

Abstract: Disclosed herein are innovations for bitstreams having clean random access (CRA) pictures and/or other types of random access point (RAP) pictures. New type definitions and strategic constraints on types of RAP pictures can simplify mapping of units of elementary video stream data to a container format. Such innovations can help improve the ability for video coding systems to more flexibly perform adaptive video delivery, production editing, commercial insertion, and the like.

Abstract: A three-dimensional data encoding method includes: when combine coding including (i) combining pieces of point cloud data to generate combined point cloud data and (ii) encoding the combined point cloud data is performed: setting first information to a first value, and generating a bitstream including the first information set, the first information indicating whether there is a possibility that each leaf node includes three-dimensional points, the first value indicating that there is the possibility that the leaf node includes the three-dimensional points; and when the combine coding is not performed: setting the first information to the first value or a second value, and generating a bitstream including the first information set, the second value indicating that there is no possibility that the leaf node includes the three-dimensional points.

Abstract: An encoder includes circuitry, and memory coupled to the circuitry. The circuitry, in operation, for each of a plurality of sub-bitstreams having mutually different frame rates, encodes identification information into a header of a bitstream including the plurality of sub-bitstreams, the identification information indicating a temporal ID that is an identifier of a temporal layer related to a temporal scalability and corresponds to the sub-bitstream, and encodes level information indicating a conformance level of the sub-bitstream.

Abstract: Several techniques for video encoding and video decoding are described. A method for video processing includes performing a conversion between a video block of a video and a bitstream of the video, wherein the video block uses a low frequency non-separable transform for the conversion, wherein the bitstream conforms to a format rule that specifies that a syntax element is included at a syntax level for the bitstream, wherein the syntax element is indicative of whether use of a scaling matrix which is derived from a reference scaling list is enabled for the video block, and wherein the syntax level is a sequence level, a picture level, or a slice level.

Abstract: A method and system for decoding a coded video sequence may include obtaining the coded video sequence, and decoding the coded video sequence. A value of a temporal sublayer identifier of a video coding layer (VCL) network abstraction layer (NAL) unit in the coded video sequence is constrained to be less than or equal to a value of vps_max_sublayers_minus1, that specifies a maximum number of temporal sublayers that may be present in a layer in each coded video sequence referring to the video parameter set (VPS), in the VPS referred to by the VCL NAL unit.

Abstract: A method of decoding JVET video, comprising defining a coding unit (CU) template within a decoded area of a video frame, the CU template being positioned above and/or to the left of a current decoding position for which data was intra predicted, defining a search window within the decoded area, the search window being adjacent to the CU template, generating a plurality of candidate prediction templates based on pixel values in the search window, each of the plurality of candidate prediction templates being generated using different intra prediction modes, calculating a matching cost between the CU template and each of the plurality of candidate prediction templates, selecting an intra prediction mode that generated the candidate prediction template that had the lowest matching cost relative to the CU template, and generating a prediction CU for the current decoding position based on the intra prediction mode.

Abstract: An image encoding/decoding method is provided. An image decoding method of the present invention may comprise deriving an intra-prediction mode of a current luma block, deriving an intra-prediction mode of a current chroma block based on the intra-prediction mode of the current luma block, generating a prediction block of the current chroma block based on the intra-prediction mode of the current chroma block, and the deriving of an intra-prediction mode of a current chroma block may comprise determining whether or not CCLM (Cross-Component Linear Mode) can be performed for the current chroma block.

Abstract: Devices, systems and methods for digital video coding, which includes context modeling and multiple transform matrix selection, are described. An exemplary method for video processing includes determining, for a conversion between a current video block of a video and a bitstream representation of the video, that an indication of a transform type in a multiple transform selection (MTS) operation is excluded from the bitstream representation, and wherein the current video block is coded using an intra block copy mode, and performing the conversion, wherein the indication is in a sequence parameter set, a picture parameter set, a tile group header, a slice header, a picture header, a tile header, a coding tree unit row, or a video data unit, and wherein the MTS operation includes using a transform from a plurality of predefined transform candidates for transforming a prediction error of the current video block during the conversion.

Abstract: A method for video processing is provided. The method includes determining, for a conversion between a current video block of a video that is a chroma block and a coded representation of the video, multiple sets of parameters, wherein each set of parameters defines a cross-component linear model (CCLM) and is derived from a corresponding group of chroma samples at corresponding chroma sample positions; determining, based on the multiple sets of parameters, parameters for a final CCLM; and performing the conversion based on the final CCLM.

Abstract: A method for colour component prediction, an encoder, a decoder and a storage medium are provided. The method includes that: prediction parameters of a current block are determined, the prediction parameters including a prediction mode parameter and a size parameter of the current block; when the prediction mode parameter indicates that a Matrix-based Intra Prediction (MIP) mode is adopted to determine an intra prediction value of the current block, an MIP weight matrix of the current block, a shift factor of the current block and an MIP input sample matrix of the current block are determined; and the intra prediction value of the current block is determined according to the MIP weight matrix, the shift factor and the MIP input sample matrix.

Abstract: Aspects of the disclosure provide a method and an apparatus including processing circuitry for video decoding. The processing circuitry decodes coded information for a transform block (TB) from a coded video bitstream. The coded information indicates one of intra prediction mode information that indicates an intra prediction mode used for the TB, a size of the TB, and a primary transform type used for the TB. The processing circuitry determines a context for entropy decoding a secondary transform index based on the one of the intra prediction mode information for the TB, the size of the TB, and the primary transform type used for the TB. The secondary transform index indicates a secondary transform in a set of secondary transforms that is to be performed on the TB. The processing circuitry entropy decodes the secondary transform index based on the context and performs the secondary transform.

Abstract: Methods, devices, and systems related to video processing are disclosed. In one example aspect, a method of video processing includes performing a conversion between a block of a current picture of a video and a coded representation of the video using an intra-subblock partitioning (ISP) mode. A prediction is determined for each sub-partition using an intra-prediction process based on samples in the current picture using the ISP mode. The block is partitioned into multiple sub-partitions including a first sub-partitions having a same top-left corner position as a top-left corner position of the block.

Abstract: A method for luma-based chroma intra-prediction in a video encoder or a video decoder is provided that includes filtering reconstructed neighboring samples of a reconstructed down sampled luma block, computing parameters ? and ? of a linear model using the filtered, reconstructed neighboring samples of the reconstructed down sampled luma block and reconstructed neighboring samples of a corresponding chroma block, wherein the linear model is PredC[x,y]=?·RecL?[x,y]+?, wherein x and y are sample coordinates, PredC is predicted chroma samples, and RecL? is samples of the reconstructed down sampled luma block, and computing samples of a predicted chroma block from corresponding samples of the reconstructed down sampled luma block using the linear model and the parameters.

Abstract: Systems, methods and apparatus for video processing are described. The video processing may include video encoding, video decoding, or video transcoding. One example method of video processing includes performing a conversion between a video including one or more pictures and a bitstream of the video according to a format rule. The format rule specifies that a first syntax element that indicates whether motion vector difference for a particular reference picture list (RPL) is indicated is conditionally included in the bitstream based on (i) whether a second syntax element indicating whether an RPL information is included in a picture header and/or (ii) a number of reference pictures in the particular RPL in case that the RPL information is present in the picture header.

Abstract: A method for decoding an image according to the present invention comprises the steps of: receiving and decoding MPM index information for indicating an MPM candidate which is to be used as an intra prediction mode of a current block; generating an MPM candidate list containing a plurality of MPM candidates for the current block; determining the MPM candidate indicated by the decoded MPM index information as the intra prediction mode of the current block, among the plurality of the MPM candidates which constitute the MPM candidate list; and generating a prediction block corresponding to the current block by performing intra prediction for the current block based on the determined intra prediction mode.

Abstract: Devices, systems and methods for palette mode coding are described. An exemplary method for video processing includes performing a conversion between a block of a video and a bitstream representation of the video. The bitstream representation is processed according to a format rule that specifies a first indication of usage of a palette mode and a second indication of usage of an intra block copy (IBC) mode are signaled dependent of each other.

Abstract: A decoding method is disclosed that comprises: determining whether a current block of a picture extends beyond a boundary of the picture; determining for each split mode of a plurality of split modes whether said current block is allowed to undergo splitting according to said split mode by checking whether at least one of the split line is co-located with one of the picture border or whether the size of the block part inside the picture along the picture boundary is a multiple of a minimum block size; decoding from a bitstream a current split mode of the current block responsive to the allowed split modes; and decoding the current block according to the current split mode.

Abstract: The present invention relates to an image information decoding method. The decoding method includes receiving a bit stream including a Network Abstraction Layer (NAL) unit that includes information related to encoded image, and parsing a NAL unit header of the NAL unit. The NAL unit header may not include 1 bit flag information that represents whether a picture is a non-reference picture or a reference picture in the entire bit stream during encoding.

Abstract: According to the disclosure of the present document, weight index information for sub-block merge candidates of a current block can be derived and coding efficiency can be increased.

Abstract: Aspects of the disclosure provide a method and an apparatus for video decoding. The apparatus includes processing circuitry receiving prediction information of a plurality of blocks in a current picture from a coded video bitstream. The processing circuitry determines, based on the prediction information, whether at least one of a decoder-side motion vector refinement (DMVR) mode or a bi-directional optical flow (BDOF) mode is allowed for the plurality of blocks. If the DMVR mode or the BDOF mode is allowed for the plurality of blocks, the processing circuitry determines that a plurality of merge with motion vector difference (MMVD) merge flags indicating whether a MMVD mode is applied to the plurality of blocks, respectively, is inferred as false for the plurality of blocks. If the plurality of MMVD merge flags is inferred as false, the processing circuitry reconstructs each block in the plurality of blocks without applying the MMVD mode.

Abstract: A method of video decoding in a decoder is provided. A first template magnitude of a first transform coefficient in a specific frequency region of the transform block is determined. The first template magnitude is a first single value representing magnitudes of a first local template of the first transform coefficient. A first context model is identified for coding the syntax element of the first transform coefficient, the first context model being shared with at least a second transform coefficient in the specific frequency region of the transform block, a second template magnitude of the second transform coefficient having a second single value that belongs to a first subinterval. A first bin of the syntax element of the first transform coefficient and a second bin of the syntax element of the second transform coefficient is determined, from the coded bits, based on the first context model.

Abstract: The image decoding method includes: determining a context for use in a current block to be processed, from among a plurality of contexts; and performing arithmetic decoding on a bit sequence corresponding to the current block, using the determined context, wherein in the determining: the context is determined under a condition that control parameters of neighboring blocks of the current block are used, when the signal type is a first type, the neighboring blocks being a left block and an upper block of the current block; and the context is determined under a condition that the control parameter of the upper block is not used, when the signal type is a second type.

Abstract: Disclosed is an apparatus for decoding motion information in merge mode for reconstructing a moving picture signal coded at a low data rate while maintaining a high quality of an image. The apparatus for decoding motion information in merge mode discloses the position of a merge mode candidate and the configuration of a candidate in order to predict motion information in merge mode efficiently. Furthermore, a merge candidate indicated by the merge index of a current block can be efficiently reconstructed irrespective of a network environment by adaptively generating a merge candidate based on the number of valid merge candidate.