Configuration data is obtained and is useable by a decoder to reconstruct a first representation of an image at a first level of quality using a second representation of the image at the first level of quality. The second representation is based on a representation of the image at a second, lower level of quality. The configuration data comprises a value of a configuration parameter, the value having a variable bit-length. The configuration data is arranged into a sequence of bytes comprising a variable-length element arranged to store the value of the configuration parameter. The variable-length element comprises at least one given byte having one or more predetermined bits arranged to indicate whether or not the variable-length element comprises one or more additional bytes to the at least one given byte. The sequence of bytes is output for processing by the decoder.

A method for processing a video signal using an affine motion prediction is disclosed. The method includes checking that a current block is encoded by the affine motion prediction, obtaining motion vectors for a plurality of control points of the current block, determining a motion vector for each of a plurality of subblocks included in the current block based on the motion vectors for the plurality of control points, and performing a prediction for the current block from the motion vector for each of the plurality of subblocks, wherein each of the plurality of subblocks is configured to have a pre-defined width and a pre-defined height.

An inter prediction method includes obtaining predicted motion information of a current image block, where the predicted motion information is used to obtain one or more motion vectors of the current image block, the motion vectors include a forward MV and a backward MV for a bidirectional inter prediction, determining a motion vector difference for the current image block, and calculating the motion vectors based on the predicted motion information and the motion vector difference, where the motion vector difference is shared by the forward MV and the backward MV.

An inter prediction method includes obtaining predicted motion information of a current image block, where the predicted motion information is used to obtain one or more motion vectors of the current image block, the motion vectors include a forward MV and a backward MV for a bidirectional inter prediction, determining a motion vector difference for the current image block, and calculating the motion vectors based on the predicted motion information and the motion vector difference, where the motion vector difference is shared by the forward MV and the backward MV.

The present invention relates to an image encoding/decoding method and apparatus. The image decoding method according to the present invention may comprise configuring an MPM list based on intra-prediction modes of neighbor blocks of a current block and a number of frequencies of the intra-prediction modes of the neighbor blocks, deriving an intra-prediction mode of the current block based on the MPM list, and performing intra-prediction for the current block based on the intra-prediction mode.

Apparatus and methods for encoding and decoding video data having improved quantization parameter prediction are presented and can include using a combination of quantization parameter prediction values obtained from respective ones of a plurality of quantization parameter prediction methods to encode or decode the video data.

A prediction method for an image block comprising a first prediction sub-block and a second prediction sub-block, the prediction method comprising: parsing a first index from a bitstream, wherein the first index is used to obtain prediction information of the first prediction sub-block; parsing a second index from the bitstream; comparing the first index with the second index; adjusting the second index in the event that the second index is equal to or greater than the first index; and obtaining prediction information of the second prediction sub-block according to the adjusted second index.

A method for intra prediction comprises determining a first MPM candidate corresponding to a left-side candidate block on the basis of a position of the left-side candidate block adjacent to a left side of a current block; determining a second MPM candidate corresponding to an upper-end candidate block on the basis of a position of the upper-end candidate block adjacent to an upper end of the current block; generating an MPM candidate list including a plurality of MPM candidates, on the basis of the first MPM candidate and the second MPM candidate; and determining one MPM candidate of the plurality of the MPM candidates that constitute the MPM candidate list as an intra prediction mode of the current block, and performing intra prediction for the current block on the basis of the determined intra prediction mode to generate a prediction block corresponding to the current block.

A method for intra prediction comprises determining a first MPM candidate corresponding to a left-side candidate block on the basis of a position of the left-side candidate block adjacent to a left side of a current block; determining a second MPM candidate corresponding to an upper-end candidate block on the basis of a position of the upper-end candidate block adjacent to an upper end of the current block; generating an MPM candidate list including a plurality of MPM candidates, on the basis of the first MPM candidate and the second MPM candidate; and determining one MPM candidate of the plurality of the MPM candidates that constitute the MPM candidate list as an intra prediction mode of the current block, and performing intra prediction for the current block on the basis of the determined intra prediction mode to generate a prediction block corresponding to the current block.

A method for decoding a video according to the present invention may comprise: decoding information indicating whether a non-zero transform coefficient exists in a current block, when the information indicates that the non-zero transform coefficient exists in the current block, determining a scanning order of the current block, and decoding a transform coefficient included in the current block according to the determined scanning order.