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EP-4542988-B1 - VIDEO SIGNAL PROCESSING METHOD AND DEVICE

EP4542988B1EP 4542988 B1EP4542988 B1EP 4542988B1EP-4542988-B1

Inventors

  • KO, Geonjung
  • KIM, DONGCHEOL
  • SON, JUHYUNG
  • JUNG, JAEHONG
  • KWAK, JINSAM

Dates

Publication Date
20260513
Application Date
20200724

Claims (5)

  1. A method for decoding a video signal, the method comprising: obtaining chroma component format information from a higher-level bitstream, the chroma component format information indicating a chroma format of a chroma component of a current block; and obtaining, based on the chroma component format information, width-related information (SubWidthC) which indicates a width of a chroma array in comparison with a width of a luma array of the current block and height-related information (SubHeightC) which indicates a height of the chroma array in comparison with a height of the luma array of the current block, characterised by obtaining x-axis scale information based on the width-related information or information on a color component of the current block; obtaining y-axis scale information based on the height-related information or the information on the color component of the current block; determining a location of a left block as ( xCb - 1, yCb - 1 + ( cbHeight << scallFactHeight) ), where xCb is an x-axis coordinate of a top-left sample of a current luma block, yCb is a y-axis coordinate of the top-left sample of the current luma block, cbHeight is a value of a height of the current block, and scallFactHeight is the y-axis scale information; determining a location of an upper block as ( xCb - 1 + (cbWidth << scallFactWidth), yCb - 1 ), where xCb is the x-axis coordinate of the top-left sample of the current luma block, yCb is the y-axis coordinate of the top-left sample of the current luma block, cbWidth is a value of a width of the current block, and scallFactWidth is the x-axis scale information; determining a weighting value based on code information of the left block and code information of the upper block, wherein if the left block is available, and a prediction mode of the left block is an intra prediction, the code information (isIntraCodedNeighbourA) of the left block is set to TRUE, wherein if the left block is not available, or the prediction mode of the left block is not the intra prediction, the code information of the left block is set to FALSE, wherein if the upper block is available, and a prediction mode of the upper block is the intra prediction, the code information (isIntraCodedNeighbourB) of the upper block is set to TRUE, and wherein if the upper block is not available, or the prediction mode of the upper block is not the intra prediction, the code information of the upper block is set to FALSE; obtaining first samples by predicting the current block in a merge mode; obtaining second samples by predicting the current block in an intra mode; and predicting the current block based on predSamplesComb[ x ][ y ] = ( w * predSamplesIntra[ x ][ y ] +( 4 - w ) * predSamplesInter[ x ][ y ] + 2) >> 2, where predSamplesComb refers to a combination prediction sample, w refers to the weighting value, predSamplesIntra refers to the second samples, predSamplesInter refers to the first samples, [x] refers to an x-axis coordinate of a sample included in the current block, and [y] refers to a y-axis coordinate of the sample included in the current block, wherein the weighting value is 3 if both the code information of the left block and the code information of the upper block are TRUE, wherein the weighting value is 1 if both the code information of the left block and the code information of the upper block are FALSE, and wherein the weighting value is 2 if only one of the code information of the left block and the code information of the upper block is TRUE.
  2. The method of claim 1, wherein the obtaining the x-axis scale information comprises: if the information on the color component of the current block is 0, or the width-related information is 1, determining the x-axis scale information to be 0; and if the information on the color component of the current block is not 0, and the width-related information is not 1, determining the x-axis scale information to be 1, and the obtaining the y-axis scale information comprises: if the information on the color component of the current block is 0, or the height-related information is 1, determining the y-axis scale information to be 0; and if the information on the color component of the current block is not 0, and the height-related information is not 1, determining the y-axis scale information to be 1.
  3. A device for decoding a video signal, the device comprising a processor and a memory, wherein, based on instructions stored in the memory, the processor is configured to: obtain chroma component format information from a higher-level bitstream, the chroma component format information indicating a chroma format of a chroma component of a current block; and obtain, based on the chroma component format information, width-related information (SubWidthC) which indicates a width of a chroma array in comparison with a width of a luma array of the current block and height-related information (SubHeightC) which indicates a height of the chroma array in comparison with a height of the luma array of the current block, characterised by obtain x-axis scale information based on the width-related information or information on a color component of the current block; obtain y-axis scale information based on the height-related information or the information on the color component of the current block; determine a location of a left block as ( xCb - 1, yCb - 1 + ( cbHeight << scallFactHeight) ), where xCb is an x-axis coordinate of a top-left sample of a current luma block, yCb is a y-axis coordinate of the top-left sample of the current luma block, cbHeight is a value of a height of the current block, and scallFactHeight is the y-axis scale information; determine a location of an upper block as ( xCb - 1 + (cbWidth << scallFactWidth), yCb - 1 ), where xCb is the x-axis coordinate of the top-left sample of the current luma block, yCb is the y-axis coordinate of the top-left sample of the current luma block, cbWidth is a value of a width of the current block, and scallFactWidth is the x-axis scale information; determine a weighting value based on code information of the left block and code information of the upper block, wherein if the left block is available, and a prediction mode of the left block is an intra prediction, the code information (isIntraCodedNeighbourA) of the left block is set to TRUE, wherein if the left block is not available, or the prediction mode of the left block is not the intra prediction, the code information of the left block is set to FALSE, wherein if the upper block is available, and a prediction mode of the upper block is the intra prediction, the code information (isIntraCodedNeighbourB) of the upper block is set to TRUE, and wherein if the upper block is not available, or the prediction mode of the upper block is not the intra prediction, the code information of the upper block is set to FALSE; obtain first samples by predicting the current block in a merge mode; obtain second samples by predicting the current block in an intra mode; and predict the current block based on predSamplesComb[ x ][ y ] = ( w * predSamplesIntra[ x ][ y ] +( 4 - w ) * predSamplesInter[ x ][ y ] + 2) >> 2, where predSamplesComb refers to a combination prediction sample, w refers to the weighting value, predSamplesIntra refers to the second samples, predSamplesInter refers to the first samples, [x] refers to an x-axis coordinate of a sample included in the current block, and [y] refers to a y-axis coordinate of the sample included in the current block, wherein the weighting value is 3 if both the code information of the left block and the code information of the upper block are TRUE, wherein the weighting value is 1 if both the code information of the left block and the code information of the upper block are FALSE, and wherein the weighting value is 2 if only one of the code information of the left block and the code information of the upper block is TRUE.
  4. The device of claim 3, wherein, based on the instructions stored in the memory, the processor is configured to: if the information on the color component of the current block is 0, or the width-related information is 1, determine the x-axis scale information to be 0; if the information on the color component of the current block is not 0, and the width-related information is not 1, determine the x-axis scale information to be 1; if the information on the color component of the current block is 0, or the height-related information is 1, determine the y-axis scale information to be 0; and if the information on the color component of the current block is not 0, and the height-related information is not 1, determine the y-axis scale information to be 1.
  5. A method for generating a bitstream including a video signal, the method comprising: generating higher-level chroma component format information indicating a chroma format of a chroma component of a current block; and obtaining, based on the chroma component format information, width-related information (SubWidthC) which indicates a width of a chroma array in comparison with a width of a luma array of the current block and height-related information (SubHeightC) which indicates a height of the chroma array in comparison with a height of the luma array of the current block, characterised by obtaining x-axis scale information based on the width-related information or information on a color component of the current block; obtaining y-axis scale information based on the height-related information or the information on the color component of the current block; determining a location of a left block as ( xCb - 1, yCb - 1 + ( cbHeight << scallFactHeight) ), where xCb is an x-axis coordinate of a top-left sample of a current luma block, yCb is a y-axis coordinate of the top-left sample of the current luma block, cbHeight is a value of a height of the current block, and scallFactHeight is the y-axis scale information; determining a location of an upper block as ( xCb - 1 + (cbWidth << scallFactWidth), yCb - 1 ), where xCb is the x-axis coordinate of the top-left sample of the current luma block, yCb is the y-axis coordinate of the top-left sample of the current luma block, cbWidth is a value of a width of the current block, and scallFactWidth is the x-axis scale information; determining a weighting value based on code information of the left block and code information of the upper block, wherein if the left block is available, and a prediction mode of the left block is an intra prediction, the code information (isIntraCodedNeighbourA) of the left block is set to TRUE, wherein if the left block is not available, or the prediction mode of the left block is not the intra prediction, the code information of the left block is set to FALSE, wherein if the upper block is available, and a prediction mode of the upper block is the intra prediction, the code information (isIntraCodedNeighbourB) of the upper block is set to TRUE, and wherein if the upper block is not available, or the prediction mode of the upper block is not the intra prediction, the code information of the upper block is set to FALSE; obtaining first samples by predicting the current block in a merge mode; obtaining second samples by predicting the current block in an intra mode; and predicting the current block based on predSamplesComb[ x ][ y ] = ( w * predSamplesIntra[ x ][ y ] +( 4 - w ) * predSamplesInter[ x ][ y ] + 2) >> 2, where predSamplesComb refers to a combination prediction sample, w refers to the weighting value, predSamplesIntra refers to the second samples, predSamplesInter refers to the first samples, [x] refers to an x-axis coordinate of a sample included in the current block, and [y] refers to a y-axis coordinate of the sample included in the current block, wherein the weighting value is 3 if both the code information of the left block and the code information of the upper block are TRUE, wherein the weighting value is 1 if both the code information of the left block and the code information of the upper block are FALSE, and wherein the weighting value is 2 if only one of the code information of the left block and the code information of the upper block is TRUE.

Description

Technical Field The present disclosure relates to a video signal processing method and device and, more specifically, to a video signal processing method and device for encoding or decoding a video signal. Background Art Compression coding refers to a series of signal processing techniques for transmitting digitized information through a communication line or storing information in a form suitable for a storage medium. An object of compression encoding includes objects such as voice, video, and text, and in particular, a technique for performing compression encoding on an image is referred to as video compression. Compression coding for a video signal is performed by removing excess information in consideration of spatial correlation, temporal correlation, and stochastic correlation. However, with the recent development of various media and data transmission media, a more efficient video signal processing method and apparatus are required. Bross et al., Joint Video Experts Team (JVET) of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29/WG 11, 13th Meeting, Marrakech, MA, 9-18 Jan. 2019, "Versatile Video Coding (Draft 4)" discloses, in section 8.5.7.6, a weighted sample prediction process for combined merge and intra prediction. Joint Video Experts Team (JVET) of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29/WG 11, 15th Meeting, Gothenburg, SE, 3-12 July 2019, discloses, in section 8.5.6.6, a weighted sample prediction process for combined merge and intra prediction Disclosure of Invention Technical Problem An objective of the present disclosure is to improve the coding efficiency of a video signal. Solution to Problem The invention includes a method for decoding a video signal in accordance with claim 1, a device for decoding a video signal in accordance with claim 3, and a method for generating a bitstream including a video signal in accordance with claim 5. Further embodiments of the invention are given in the dependent claims. Advantageous Effects of Invention According to an embodiment of the present invention, coding efficiency of a video signal can be improved. Brief Description of Drawings FIG. 1 is a schematic block diagram of a video signal encoding apparatus according to an embodiment of the present invention.FIG. 2 is a schematic block diagram of a video signal decoding apparatus according to an embodiment of the present invention.FIG. 3 shows an embodiment in which a coding tree unit is divided into coding units in a picture.FIG. 4 shows an embodiment of a method for signaling a division of a quad tree and a multi-type tree.FIGS. 5 and 6 illustrate an intra-prediction method in more detail according to an embodiment of the present disclosure.FIG. 7 illustrates an inter prediction method according to an embodiment of the present disclosure.FIG. 8 is a diagram illustrating a method in which a motion vector of a current block is signaled, according to an embodiment of the present disclosure;FIG. 9 is a diagram illustrating a method in which a motion vector difference value of a current block is signaled, according to an embodiment of the present disclosure;FIG. 10 is a diagram illustrating adaptive motion vector resolution signaling according to an embodiment of the present disclosure;FIG. 11 is a diagram illustrating inter prediction-related syntax according to an embodiment of the present disclosure;FIG. 12 is a diagram illustrating multi-hypothesis prediction according to an embodiment of the present disclosure;FIG. 13 is a diagram illustrating multi-hypothesis prediction-related syntax according to an embodiment of the present disclosure;FIG. 14 is a diagram illustrating multi-hypothesis prediction-related syntax according to an embodiment of the present disclosure;FIG. 15 is a diagram illustrating multi-hypothesis prediction-related syntax according to an embodiment of the present disclosure;FIG. 16 is a diagram illustrating a method of determining a multi-hypothesis prediction mode according to an embodiment of the present disclosure;FIG. 17 is a diagram illustrating a method of generating a candidate list according to an embodiment of the present disclosure;FIG. 18 is a diagram illustrating neighboring locations referenced in multi-hypothesis prediction according to an embodiment of the present disclosure;FIG. 19 is a diagram illustrating a method of referencing neighboring modes according to an embodiment of the present disclosure;FIG. 20 is a diagram illustrating a method of generating a candidate list according to an embodiment of the present disclosure;FIG. 21 is a diagram illustrating a method of generating a candidate list according to an embodiment of the present disclosure;FIG. 22 is a diagram illustrating neighboring locations referenced in multi-hypothesis prediction according to an embodiment of the present disclosure;FIG. 23 is a diagram illustrating a method of referencing neighboring modes according to an embodiment of the present disclosure;FIG. 24 is a diagram illustrating use of a neighb