Abstract: An image encoding and decoding method and apparatus are provided. The image decoding method includes obtaining a difference quantization parameter for a current coding unit from a bitstream, based on an area of a predefined difference quantization parameter signaling unit; obtaining a quantization parameter for the current coding unit by using a predicted quantization parameter for the current coding unit and the difference quantization parameter for the current coding unit; obtaining at least one inverse-quantized coefficient by performing inverse-quantization on at least one coefficient obtained based on residual information of the current coding unit included in the bitstream, based on the quantization parameter for the current coding unit; obtaining a residual block of the current coding unit, based on the inverse-quantized coefficient; and obtaining a reconstructed block of the current coding unit, based on the residual block of the current coding unit.

Abstract: Provided is an image decoding method including: obtaining, from a bitstream, a syntax element regarding multiple transform selection (MTS) with respect to a current coding unit or a current transform unit included in the current coding unit; determining a horizontal transform kernel or a vertical transform kernel with respect to the current transform unit based on the obtained syntax element; obtaining a residual signal by performing inverse transformation on the current transform unit, based on the determined horizontal transform kernel or vertical transform kernel with respect to the current transform unit; and generating a reconstruction block including the current coding unit or the current transform unit based on the residual signal with respect to the current transform unit.

Abstract: Provided is a video decoding method including: generating a merge candidate list including neighboring blocks referred to to predict a motion vector of a current block in a skip mode or a merge mode; when a merge motion vector difference is used according to merge difference mode information indicating whether the merge motion vector difference and a motion vector determined from the merge candidate list are used, determining a base motion vector from a candidate determined among the merge candidate list based on merge candidate information; determining the motion vector of the current block by using the base motion vector and a merge motion vector difference of the current block, the merge motion vector difference being determined by using a distance index and direction index of the merge motion vector difference of the current block; and reconstructing the current block by using the motion vector of the current block.

Abstract: Provided is a video decoding method including: obtaining, from a sequence parameter set, sequence merge mode with motion vector difference (sequence MMVD) information indicating whether an MMVD mode is applicable in a current sequence; when the MMVD mode is applicable according to the sequence MMVD information, obtaining, from a bitstream, first MMVD information indicating whether the MMVD mode is applied in a first inter prediction mode for a current block included in the current sequence; when the MMVD mode is applicable in the first inter prediction mode according to the first MMVD information, reconstructing a motion vector of the current block which is to be used in the first inter prediction mode, by using a distance of a motion vector difference and a direction of a motion vector difference obtained from the bitstream; and reconstructing the current block by using the motion vector of the current block.

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: Provided are a video encoding or decoding method and apparatus, which, during video encoding and decoding processes, determine whether an intra prediction mode of the current block is a DC mode, when the intra prediction mode of the current block is the DC mode, in a case where lengths of a height and a width of the current block are the same, determine an average of upper reference samples of the current block and left reference samples of the current block, as a DC value, and in a case where the lengths of the height and the width of the current block are different from each other, determine a weighted average value, which is determined by determining an average of the upper reference samples of the current block as an upper DC value, determine an average of the left reference samples of the current block as a left DC value, and combining the upper value and the left DC value with a predetermined weight, as a DC value, and perform intra prediction on the current block, based on the DC value.

Abstract: An apparatus and a method for controlling a recording operation for a video cassette recorder system having a digital tuner, prevent broadcast signals from being combined with menu screen data when a GUI is activated in the course of a watching and a recording operations. The apparatus and the method check whether the GUI is activated, and then performs an automatic switching operation so as to record the broadcast signals before menu screen data generated from the GUI are combined with the broadcast signals if the GUI is activated. Therefore, the apparatus and the method basically prevents the menu screen data from being combined with the broadcast signals.

Abstract: An apparatus and a method for controlling a recording operation for a video cassette recorder system having a digital tuner, prevent broadcast signals from being combined with menu screen data when a GUI is activated in the course of a watching and a recording operations. The apparatus and the method check whether the GUI is activated, and then performs an automatic switching operation so as to record the broadcast signals before menu screen data generated from the GUI are combined with the broadcast signals if the GUI is activated. Therefore, the apparatus and the method basically prevents the menu screen data from being combined with the broadcast signals.