Method and device for video processing and medium

Abstract

Embodiments of the present disclosure provide a scheme for video processing. A method for video processing is presented. The method comprises: for a conversion between a current video block of a video and a bitstream of the video, generating a list of motion candidates for the current video block, an adjustment process being applied to a plurality of samples of the current video block; and performing a conversion based on the motion candidate list.

Description

Technical Field

[0001] Embodiments of the present disclosure relate generally to video processing techniques, and more particularly to sample adjustment. Background Art

[0002] Nowadays, digital video capabilities are being applied to all aspects of people's lives. For video encoding / decoding, various types of video compression technologies have been proposed, such as MPEG-2, MPEG-4, ITU-T H.263, ITU-TH.264 / MPEG-4 Part 10 Advanced Video Codec (AVC), ITU-T H.265 High Efficiency Video Codec (HEVC) standard, and Versatile Video Codec (VVC) standard. However, it is generally expected that the encoding and decoding efficiency of video encoding and decoding technologies can be further improved. Summary of the invention

[0003] Embodiments of the present disclosure provide a solution for video processing.

[0004] In a first aspect, a method for video processing is proposed. The method includes: for conversion between a current video block of a video and a bitstream of the video, generating a motion candidate list for the current video block, an adjustment process being applied to a plurality of samples of the current video block; and performing conversion based on the motion candidate list.

[0005] According to the method of the first aspect of the present disclosure, a motion candidate list is generated for a video block, and its samples are adjusted based on an adjustment process. Compared with the traditional scheme, the proposed method can advantageously better support sample adjustment, thereby achieving higher codec gain and improving codec efficiency.

[0006] In a second aspect, another method for video processing is provided. The method includes: determining cost information associated with an adjustment process, in which samples of the video block are adjusted, based on codec information of the video for a conversion between a current video block of the video and a bitstream of the video; determining target information about the adjustment process for the current video block based on the cost information; and performing the conversion based on the target information.

[0007] According to the method of the second aspect of the present disclosure, information about the adjustment process is implicitly determined from the codec information. Compared with the traditional scheme, the proposed method can advantageously better support sample adjustment, thereby achieving higher codec gain and improving codec efficiency.

[0008] In a third aspect, a device for video processing is provided. The device includes a processor and a non-volatile memory having instructions thereon. The instructions, when executed by the processor, cause the processor to perform the method according to the first aspect or the second aspect of the present disclosure.

[0009] In a fourth aspect, a non-transitory computer-readable storage medium is provided, wherein the non-transitory computer-readable storage medium stores instructions for causing a processor to execute the method according to the first aspect or the second aspect of the present disclosure.

[0010] In a fifth aspect, another non-transitory computer-readable recording medium is provided. The non-transitory computer-readable recording medium stores a bitstream of a video generated by a method performed by an apparatus for video processing. The method includes: generating a motion candidate list for a current video block of the video, the adjustment process being applied to multiple samples of the current video block; and generating a bitstream based on the motion candidate list.

[0011] In a sixth aspect, a method for storing a bitstream of a video is provided. The method includes: generating a motion candidate list for a current video block of the video, the adjustment process being applied to multiple samples of the current video block; generating a bitstream based on the motion candidate list; and storing the bitstream in a non-transitory computer-readable recording medium.

[0012] In a seventh aspect, another non-transitory computer-readable recording medium is provided. The non-transitory computer-readable recording medium stores a bitstream of a video generated by a method performed by an apparatus for video processing. The method includes: determining cost information associated with an adjustment process based on codec information of the video, in which samples of a video block are adjusted; determining target information about the adjustment process for a current video block of the video based on the cost information; and generating a bitstream based on the target information.

[0013] In an eighth aspect, a method for storing a bitstream of a video is provided. The method includes: determining cost information associated with an adjustment process, in which samples of a video block are adjusted, based on codec information of the video; determining target information about the adjustment process for a current video block of the video based on the cost information; generating a bitstream based on the target information; and storing the bitstream in a non-transitory computer-readable recording medium.

[0014] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the disclosure, nor is it intended to limit the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other objects, features and advantages of the exemplary embodiments of the present disclosure will become more apparent through the following detailed description with reference to the accompanying drawings. In the exemplary embodiments of the present disclosure, the same reference numerals generally refer to the same components.

[0016] Figure 1A block diagram showing an example video encoding and decoding system according to some embodiments of the present disclosure is shown;

[0017] Figure 2 A block diagram of a first example video encoder according to some embodiments of the present disclosure is shown;

[0018] Figure 3 A block diagram of an example video decoder according to some embodiments of the present disclosure is shown;

[0019] Figure 4 The current coding tree unit (CTU) processing order and its available reference samples in the current and left CTUs are shown;

[0020] Figure 5 The residual encoding and decoding pass for transforming a skipped block is shown;

[0021] Figure 6 An example of a block encoded and decoded in palette mode is shown;

[0022] Figure 7 A sub-block based index map scan for a palette is shown;

[0023] Figure 8 A decoding flow chart with adaptive color transform (ACT) is shown;

[0024] Fig. 9 The intra-frame template matching search area used is shown;

[0025] Fig.10 A flowchart of a method for video processing according to an embodiment of the present disclosure is shown;

[0026] Fig.11 A flowchart of another method for video processing according to an embodiment of the present disclosure is shown; and

[0027] Fig.12 A block diagram of a computing device is shown in which various embodiments of the present disclosure may be implemented.

[0028] Throughout the drawings, same or similar reference numbers generally refer to same or similar elements. DETAILED DESCRIPTION

[0029] The principle of the present disclosure will now be described with reference to some embodiments. It should be understood that these embodiments are described only for the purpose of illustrating and helping those skilled in the art to understand and implement the present disclosure, without implying any limitation on the scope of the present disclosure. In addition to the methods described below, the disclosure described herein can also be implemented in various ways.

[0030] In the following description and claims, unless defined otherwise, all scientific and technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs.

[0031] References in this disclosure to "one embodiment," "an embodiment," "an example embodiment," etc. indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment must include the particular feature, structure, or characteristic. Furthermore, these phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in conjunction with an example embodiment, whether or not explicitly described, it is considered to be within the knowledge of those skilled in the art to affect such feature, structure, or characteristic in relation to other embodiments.

[0032] It should be understood that although the terms "first" and "second" etc. can be used to describe various elements, these elements should not be limited to these terms. These terms are only used to distinguish one element from another element. For example, a first element can be referred to as a second element, and similarly, a second element can be referred to as a first element without departing from the scope of the exemplary embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0033] The terms used herein are only used for the purpose of describing specific embodiments and are not intended to limit the exemplary embodiments. As used herein, the singular forms "a", "an", and "the" are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms "comprises", "includes", and / or "having" when used herein indicate the presence of the features, elements, and / or components, etc., but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Example Environment

[0034] Figure 1 1 is a block diagram illustrating an example video codec system 100 that can utilize the techniques of the present disclosure. As shown, the video codec system 100 may include a source device 110 and a destination device 120. The source device 110 may also be referred to as a video encoding device, and the destination device 120 may also be referred to as a video decoding device. In operation, the source device 110 may be configured to generate encoded video data, and the destination device 120 may be configured to decode the encoded video data generated by the source device 110. The source device 110 may include a video source 112, a video encoder 114, and an input / output (I / O) interface 116.

[0035] Video source 112 may include a source such as a video capture device. Examples of a video capture device include, but are not limited to, an interface that receives video data from a video content provider, a computer graphics system for generating video data, and / or combinations thereof.

[0036] The video data may include one or more pictures. The video encoder 114 encodes the video data from the video source 112 to generate a bitstream. The bitstream may include a bit sequence that forms a codec representation of the video data. The bitstream may include a codec picture and associated data. The codec picture is a codec representation of the picture. The associated data may include a sequence parameter set, a picture parameter set, and other grammatical structures. The I / O interface 116 may include a modulator / demodulator and / or a transmitter. The encoded video data may be directly transmitted to the destination device 120 via the network 130A via the I / O interface 116. The encoded video data may also be stored on a storage medium / server 130B for access by the destination device 120.

[0037] The destination device 120 may include an I / O interface 126, a video decoder 124, and a display device 122. The I / O interface 126 may include a receiver and / or a modem. The I / O interface 126 may obtain encoded video data from the source device 110 or the storage medium / server 130B. The video decoder 124 may decode the encoded video data. The display device 122 may display the decoded video data to the user. The display device 122 may be integrated with the destination device 120, or may be outside the destination device 120, which is configured to be connected to an external display device interface.

[0038] The video encoder 114 and the video decoder 124 may operate according to a video compression standard, such as the High Efficiency Video Codec (HEVC) standard, the Versatile Video Codec (VVC) standard, and other existing and / or further standards.

[0039] Figure 2 is a block diagram showing an example of a video encoder 200 according to some embodiments of the present disclosure, which may be Figure 1 An example of a video encoder 114 in the system 100 is shown.

[0040] Video encoder 200 may be configured to implement any or all of the techniques of this disclosure. Figure 2 In the example of , video encoder 200 includes multiple functional components. The techniques described in this disclosure can be shared between the various components of video encoder 200. In some examples, a processor can be configured to perform any or all of the techniques described in this disclosure.

[0041] In some embodiments, the video encoder 200 may include a partitioning unit 201, a prediction unit 202, a residual generation unit 207, a transformation unit 208, a quantization unit 209, an inverse quantization unit 210, an inverse transformation unit 211, a reconstruction unit 212, a buffer 213 and an entropy coding and decoding unit 214, and the prediction unit 202 may include a mode selection unit 203, a motion estimation unit 204, a motion compensation unit 205 and an intra-frame prediction unit 206.

[0042] In other examples, the video encoder 200 may include more, fewer, or different functional components. In one example, the prediction unit 202 may include an intra-block copy (IBC) unit. The IBC unit may perform prediction in an IBC mode, where at least one reference picture is a picture where the current video block is located.

[0043] Furthermore, although some components (such as the motion estimation unit 204 and the motion compensation unit 205) may be integrated, for the purpose of explanation, these components are described in detail below. Figure 2 are shown separately in the example.

[0044] The partitioning unit 201 may partition a picture into one or more video blocks. The video encoder 200 and the video decoder 300 may support various video block sizes.

[0045] The mode selection unit 203 may select one of a plurality of codec modes (intra-frame coding or inter-frame coding), for example, based on the error result, and provide the generated intra-frame codec block or inter-frame codec block to the residual generation unit 207 to generate residual block data, and to the reconstruction unit 212 to reconstruct the codec block for use as a reference picture. In some examples, the mode selection unit 203 may select a combination of intra-frame and inter-frame prediction (CIIP) modes, where the prediction is based on an inter-frame prediction signal and an intra-frame prediction signal. In the case of inter-frame prediction, the mode selection unit 203 may also select a resolution for the motion vector (e.g., sub-pixel precision or integer pixel precision) for the block.

[0046] To perform inter-frame prediction on the current video block, the motion estimation unit 204 may generate motion information for the current video block by comparing the current video block with one or more reference frames from the buffer 213. The motion compensation unit 205 may determine a predicted video block for the current video block based on the motion information and decoded samples of pictures from the buffer 213 other than the picture associated with the current video block.

[0047] The motion estimation unit 204 and the motion compensation unit 205 may perform different operations on the current video block, for example, depending on whether the current video block is in an I slice, a P slice, or a B slice. As used herein, an "I slice" may refer to a portion of a picture consisting of macroblocks, all of which are based on macroblocks within the same picture. Furthermore, as used herein, in some aspects, a "P slice" and a "B slice" may refer to a portion of a picture consisting of macroblocks that are independent of macroblocks in the same picture.

[0048] In some examples, the motion estimation unit 204 may perform unidirectional prediction on the current video block, and the motion estimation unit 204 may search the reference pictures of list 0 or list 1 to find the reference video block for the current video block. The motion estimation unit 204 may then generate a reference index and a motion vector, the reference index indicating the reference picture in list 0 or list 1 containing the reference video block, and the motion vector indicating the spatial displacement between the current video block and the reference video block. The motion estimation unit 204 may output the reference index, the prediction direction indicator, and the motion vector as the motion information of the current video block. The motion compensation unit 205 may generate a predicted video block for the current video block based on the reference video block indicated by the motion information of the current video block.

[0049] Alternatively, in other examples, the motion estimation unit 204 may perform bidirectional prediction on the current video block. The motion estimation unit 204 may search the reference pictures in list 0 for a reference video block for the current video block, and may also search the reference pictures in list 1 for another reference video block for the current video block. The motion estimation unit 204 may then generate a plurality of reference indexes and a plurality of motion vectors, the plurality of reference indexes indicating a plurality of reference pictures in list 0 and list 1 containing a plurality of reference video blocks, and the plurality of motion vectors indicating a plurality of spatial displacements between the plurality of reference video blocks and the current video block. The motion estimation unit 204 may output the plurality of reference indexes and the plurality of motion vectors of the current video block as motion information of the current video block. The motion compensation unit 205 may generate a predicted video block for the current video block based on the plurality of reference video blocks indicated by the motion information of the current video block.

[0050] In some examples, motion estimation unit 204 may output a complete set of motion information for use in a decoding process by a decoder. Alternatively, in some embodiments, motion estimation unit 204 may signal motion information of a current video block with reference to motion information of another video block. For example, motion estimation unit 204 may determine that motion information of a current video block is sufficiently similar to motion information of a neighboring video block.

[0051] In one example, motion estimation unit 204 may indicate to video decoder 300 a value in a syntax structure associated with the current video block that indicates that the current video block has the same motion information as another video block.

[0052] In another example, the motion estimation unit 204 may identify another video block and a motion vector difference (MVD) in a syntax structure associated with the current video block. The motion vector difference indicates the difference between the motion vector of the current video block and the motion vector of the indicated video block. The video decoder 300 may use the motion vector of the indicated video block and the motion vector difference to determine the motion vector of the current video block.

[0053] As discussed above, the video encoder 200 may signal motion vectors in a predictive manner.Two examples of prediction signaling techniques that may be implemented by the video encoder 200 include Advanced Motion Vector Prediction (AMVP) and merge mode signaling.

[0054] The intra prediction unit 206 may perform intra prediction on the current video block. When the intra prediction unit 206 performs intra prediction on the current video block, the intra prediction unit 206 may generate prediction data for the current video block based on decoded samples of other video blocks in the same picture. The prediction data for the current video block may include a prediction video block and various syntax elements.

[0055] The residual generation unit 207 may generate residual data for the current video block by subtracting (e.g., indicated by a minus sign) the prediction video block(s) of the current video block from the current video block. The residual data of the current video block may include residual video blocks corresponding to different sample portions of samples in the current video block.

[0056] In other examples, such as in skip mode, there may be no residual data for the current video block, and the residual generation unit 207 may not perform a subtraction operation.

[0057] Transform processing unit 208 may generate one or more transform coefficient video blocks for a current video block by applying one or more transforms to the residual video block associated with the current video block.

[0058] After transform processing unit 208 generates a transform coefficient video block associated with the current video block, quantization unit 209 may quantize the transform coefficient video block associated with the current video block based on one or more quantization parameter (QP) values ​​associated with the current video block.

[0059] The inverse quantization unit 210 and the inverse transform unit 211 may apply inverse quantization and inverse transform to the transform coefficient video block, respectively, to reconstruct a residual video block from the transform coefficient video block. The reconstruction unit 212 may add the reconstructed residual video block to corresponding samples from one or more prediction video blocks generated by the prediction unit 202 to generate a reconstructed video block associated with the current video block for storage in the buffer 213.

[0060] After reconstruction unit 212 reconstructs the video block, a loop filtering operation may be performed to reduce video blocking artifacts in the video block.

[0061] The entropy coding unit 214 may receive data from other functional components of the video encoder 200. When the entropy coding unit 214 receives data, the entropy coding unit 214 may perform one or more entropy coding operations to generate entropy coded data and output a bitstream including the entropy coded data.

[0062] Figure 3 is a block diagram showing an example of a video decoder 300 according to some embodiments of the present disclosure, which may be Figure 1 An example of a video decoder 124 in the system 100 is shown.

[0063] Video decoder 300 may be configured to perform any or all of the techniques of this disclosure. Figure 3 In the example of , video decoder 300 includes multiple functional components. The techniques described in this disclosure can be shared between the various components of video decoder 300. In some examples, a processor can be configured to perform any or all of the techniques described in this disclosure.

[0064] exist Figure 3 In the example of , the video decoder 300 includes an entropy decoding unit 301, a motion compensation unit 302, an intra prediction unit 303, an inverse quantization unit 304, an inverse transform unit 305, and a reconstruction unit 306 and a buffer 307. In some examples, the video decoder 300 can perform a decoding process that is generally opposite to the encoding process described with respect to the video encoder 200.

[0065] The entropy decoding unit 301 can retrieve the encoded bitstream. The encoded bitstream may include entropy encoded video data (e.g., encoded video data blocks). The entropy decoding unit 301 can decode the entropy encoded video data, and the motion compensation unit 302 can determine motion information from the entropy decoded video data, the motion information including motion vectors, motion vector precision, reference picture list indexes, and other motion information. The motion compensation unit 302 can determine the information, for example, by performing AMVP and merge mode. AMVP is used, including deriving several most likely candidates based on data and reference pictures of adjacent PBs. The motion information typically includes horizontal and vertical motion vector displacement values, one or two reference picture indexes, and in the case of prediction areas in B strips, also includes an identification of which reference picture list is associated with each index. As used herein, in some aspects, "merge mode" may refer to deriving motion information from blocks that are adjacent in space or time.

[0066] The motion compensation unit 302 may generate motion compensated blocks, possibly performing interpolation based on interpolation filters.Identifiers for the interpolation filters used with sub-pixel precision may be included in the syntax elements.

[0067] The motion compensation unit 302 may calculate interpolated values ​​for sub-integer pixels of a reference block using interpolation filters used by the video encoder 200 during encoding of the video block. The motion compensation unit 302 may determine the interpolation filters used by the video encoder 200 based on received syntax information, and the motion compensation unit 302 may use the interpolation filters to generate a prediction block.

[0068] The motion compensation unit 302 may use at least part of the syntax information to determine the size of blocks used to encode (multiple) frames and / or (multiple) slices of the encoded video sequence, partition information describing how each macroblock of a picture of the encoded video sequence is partitioned, a mode indicating how each partition is encoded, one or more reference frames (and reference frame lists) for each inter-frame coding block, and other information for decoding the encoded video sequence. As used herein, in some aspects, a "slice" may refer to a data structure that can be decoded independently of other slices of the same picture in terms of entropy coding, signal prediction, and residual signal reconstruction. A slice may be an entire picture, or it may be a region of a picture.

[0069] The intra prediction unit 303 may use, for example, an intra prediction mode received in the bitstream to form a prediction block from spatially neighboring blocks. The inverse quantization unit 304 inverse quantizes (i.e., dequantizes) the quantized video block coefficients provided in the bitstream and decoded by the entropy decoding unit 301. The inverse transform unit 305 applies an inverse transform.

[0070] The reconstruction unit 306 may obtain the decoded block, for example, by adding the residual block to the corresponding prediction block generated by the motion compensation unit 302 or the intra prediction unit 303. If necessary, a deblocking filter may also be applied to filter the decoded block to remove blocking artifacts. The decoded video block is then stored in a buffer 307, which provides reference blocks for subsequent motion compensation / intra prediction, and the buffer 307 also generates the decoded video for presentation on a display device.

[0071] Some example embodiments of the present disclosure will be described in detail below. It should be noted that the section titles used in this document are for ease of understanding, and the embodiments disclosed in the section are not limited to that section. In addition, although some embodiments are described with reference to general video codecs or other specific video codecs, the disclosed technology is also applicable to other video coding and decoding technologies. In addition, although some embodiments describe the video encoding steps in detail, it should be understood that the corresponding decoding steps of canceling the encoding will be implemented by the decoder. In addition, the term "video processing" includes video coding or compression, video decoding or decompression, and video transcoding, in which video pixels are represented from one compression format to another compression format or at different compression bit rates. 1 Brief Overview The present disclosure relates to video coding technology. Specifically, it relates to the reordering of samples in image / video coding. It can be applied to existing video coding standards such as HEVC, VVC, etc. It can also be applied to future video coding standards or video codecs. 2 Introduction Video codec standards have evolved primarily through the development of the well-known ITU-T and ISO / IEC standards. ITU-T developed H.261 and H.263, ISO / IEC developed MPEG-1 and MPEG-4 Visual, and the two organizations jointly developed H.262 / MPEG-2 Video and H.264 / MPEG-4 Advanced Video Codec (AVC) and H.265 / HEVC standards. Since H.262, video codec standards have been based on a hybrid video codec structure, in which temporal prediction plus transform codec is used. In order to explore future video codec technologies beyond HEVC, VCEG and MPEG jointly founded the Joint Video Exploration Team (JVET) in 2015. JVET meetings are held simultaneously every quarter, and the new video codec standard was officially named Versatile Video Codec (VVC) at the JVET meeting in April 2018, when the first version of the VVC Test Model (VTM) was released. The VVC working draft and the test model VTM are updated after each meeting. The VVC project achieved technical completion (FDIS) at the July 2020 meeting. 2.1 Existing Screen Content Encoding Tools 2.1.1 Intra-block copy (IBC) Intra-block copying (IBC) is a tool adopted in the HEVC extension on SCC. It is well known that it significantly improves the encoding and decoding efficiency of screen content materials. Since the IBC mode is implemented as a block-level coding mode, block matching (BM) is performed at the encoder to find the best block vector (or motion vector) for each CU. Here, the block vector is used to indicate the displacement from the current block to the reference block, which has been reconstructed within the current picture. The luminance block vector of the CU encoded and decoded by IBC has integer precision. The chrominance block vector is also rounded to integer precision. When combined with AMVR, the IBC mode can switch between 1-pixel and 4-pixel motion vector precision. The CU encoded and decoded by IBC is regarded as a third prediction mode in addition to the intra or inter prediction mode. The IBC mode is applicable to CUs whose width and height are both less than or equal to 64 luminance samples. On the encoder side, hash-based motion estimation is performed for IBC. The encoder performs RD checks on blocks with width or height no greater than 16 luma samples. For non-merge mode, a block vector search is first performed using a hash-based search. If the hash search does not return a valid candidate, a local search based on block matching is performed. In hash-based search, the hash key matching (32-bit CRC) between the current block and the reference blocks is extended to all allowed block sizes. The hash key calculation for each position in the current picture is based on 4×4 sub-blocks. For current blocks of larger size, the hash key is determined to match the hash key of the reference block when all hash keys in all 4×4 sub-blocks match the hash keys in the corresponding reference positions. If multiple reference blocks are found whose hash keys match the hash key of the current block, the block vector cost of each matching reference is calculated and the one with the smallest cost is selected. In the block matching search, the search range is set to cover the previous CTU and the current CTU. At CU level, the IBC mode is signaled through a flag, which can be signaled as IBC AMVP mode or IBC Skip / Merge mode as shown below: – IBC skip / merge mode: The merge candidate index is used to indicate which block vector from the list of neighboring candidate IBC codec blocks is used to predict the current block. The merge list consists of spatial candidates, HMVP candidates and pairwise candidates. – IBC AMVP mode: Block vector differences are encoded and decoded in the same way as motion vector differences. The block vector prediction method uses two candidates as predictors, one from the left neighbor and one from the top neighbor (if IBC coded). When either neighbor is not available, the default block vector is used as predictor. A flag is signaled to indicate the block vector predictor index. 2.1.1.1 IBC Reference Area In order to reduce memory consumption and decoder complexity, IBC in VVC only allows the reconstruction of predefined areas, which include the area of ​​the current CTU and a certain area of ​​the left CTU. Figure 4 The reference area of ​​the IBC mode is shown, where each block represents a 64×64 luma sample unit. Depending on the location of the current codec CU location within the current CTU, the following applies: – If the current block falls into the 64×64 block to the upper left of the current CTU, in addition to the samples already reconstructed in the current CTU, the CPR mode can be used to refer to the reference samples in the lower right 64x64 block of the left CTU. The current block can also use the CPR mode to refer to the reference samples in the lower left 64×64 block of the left CTU and the reference samples in the upper right 64×64 block of the left CTU. – If the current block falls into the 64×64 block to the upper right of the current CTU, in addition to the samples that have been reconstructed in the current CTU, if the luma position (0, 64) has not been reconstructed relative to the current CTU, the current block can also use the CPR mode to refer to the reference samples in the lower left 64×64 block and the lower right 64×64 block of the left CTU; Otherwise, the current block may also refer to reference samples in the lower right 64×64 block of the left CTU. – If the current block falls into the 64×64 block at the lower left of the current CTU, in addition to the samples that have been reconstructed in the current CTU, if the luma position (64, 0) has not been reconstructed relative to the current CTU, the current block can also use the CPR mode to refer to the reference samples in the upper right 64×64 block and the lower right 64×64 block of the left CTU. Otherwise, the current block can also use the CPR mode to refer to the reference samples in the lower right 64×64 block of the left CTU. – If the current block falls into the 64×64 block to the lower right of the current CTU, only the CPR mode can be used to refer to the samples that have been reconstructed in the current CTU. This restriction allows the IBC mode to be implemented using local on-chip memory for hardware implementation. 2.1.1.2 Interaction between IBC and other codecs The interaction between IBC mode and other inter-frame codec tools in VVC, such as pairwise merge candidates, history-based motion vector predictor (HMVP), combined intra / frame prediction modes (CIIP), merge mode with motion vector difference (MMVD), and geometric partition model (GPM), is as follows: – IBC can be used with pairwise merge candidates and HMVP. A new pairwise IBC merge candidate can be generated by averaging two IBC merge candidates. For HMVP, IBC motions are inserted into the history buffer for future reference. – IBC cannot be used in conjunction with the following interframe tools: Affine Motion, CIIP, MMVD, and GPM. – When DUAL_TREE partitioning is used, IBC is not allowed for chroma codec blocks. Unlike in the HEVC screen content codec extension, the current picture is no longer included as one of the reference pictures in reference picture list 0 for IBC prediction. The motion vector derivation process for IBC mode excludes all neighboring blocks in inter mode and vice versa. The following IBC design aspects are applied: – IBC shares the same process as regular MV merging, including pairwise merging candidates and history-based motion predictors, but TMVP and zero vectors are not allowed as they are invalid for IBC mode. – Separate HMVP buffers (5 candidates each) for legacy MV and IBC. – Block vector constraints are implemented as bitstream consistency constraints, where the encoder needs to ensure that there are no invalid vectors in the bitstream and that merges should not be used if the merge candidate is invalid (out of range or 0). This bitstream consistency constraint is represented by a virtual buffer as described below. – For deblocking, IBC is handled as an inter mode. – If the current block is coded using IBC prediction mode, AMVR does not use quarter pixels; instead, AMVR is signaled to only indicate whether the MV is inter-pixel or 4-integer pixels. - The number of IBC merge candidates may be signaled in the slice header separately from the number of normal, sub-block and geometric merge candidates. The concept of virtual buffer is used to describe the allowable reference area for IBC prediction mode and valid block vector. Denoting the CTU size as ctbSize, the width of the virtual buffer ibcBuf is wIbcBuf=128×128 / ctbSize, and the height hIbcBuf=ctbSize. For example, for a CTU of size 128×128, the size of ibcBuf is also 128×128; and for a CTU of size 64×64, the size of ibcBuf is 256×64; for a CTU of size 32×32, the size of ibcBuf is 512×32. The size of VPDU in each dimension is min(ctbSize, 64), Wv = min(ctbSize, 64). The virtual IBC buffer ibcBuf is maintained as follows. – At the start of decoding each CTU line, flush the entire ibcBuf with invalid value -1. – When starting to decode the VPDU (xVPDU, yVPDU) relative to the upper left corner of the picture, set ibcBuf[x][y] = -1, where x = xVPDU% wIbcBuf, …, xVPDU% wIbcBuf+Wv-1; y = yVPDU% ctbSize, …, yVPDU% ctbSize+Wv-1. –After decoding, the CU contains the (x,y) relative to the upper left corner of the picture, set ibcBuf[x%wIbcBuf][y%ctbSize]=recSample[x][y] For a block covering coordinates (x, y), it is valid if the following holds for the block vector bv = (bv[0], bv[1]); otherwise, it is invalid: ibcBuf[(x+bv[0])%wIbcBuf][(y+bv[1])%ctbSize] should not be equal to -1. 2.1.2 Block Differential Pulse Coded Modulation (BDPCM) VVC supports Block Differential Pulse Coded Modulation (BDPCM) for screen content coding. At the sequence level, the BDPCM enable flag is signaled in the SPS; this flag is signaled only when transform skip mode (described in the next section) is enabled in the SPS. When BDPCM is enabled, if the CU size is less than or equal to MaxTsSize×MaxTsSize in terms of luma samples and if the CU is intra-coded, a flag is sent at the CU level, where MaxTsSize is the maximum block size that allows transform skip mode. The flag indicates whether conventional intra-coding or BDPCM is used. If BDPCM is used, the BDPCM prediction direction flag is transmitted to indicate whether the prediction is horizontal or vertical. The block is then predicted using a conventional horizontal or vertical intra prediction process with unfiltered reference samples. The residuals are quantized, and the difference between each quantized residual and its predictor, i.e., the previously coded residual of a neighboring position horizontally or vertically (depending on the BDPCM prediction direction), is coded. For a block of size M (height) × N (width), let r i,j ,0≤i≤M-1,0≤j≤N-1 is the prediction residual. Let Q(r i,j ), 0≤i≤M-1,0≤j≤N-1 represents the residual r i,j BDPCM is applied to the quantized residual values, resulting in a quantized version of The modified M×N array in is predicted from its neighboring quantized residual values. For vertical BDPCM prediction mode, for 0≤j≤(N-1), the following is used to derive For the horizontal BDPCM prediction mode, for 0≤j≤(N-1), the following is used to derive On the decoder side, the above process is reversed to calculate Q(r i,j ), 0≤i≤M-1,0≤j≤N-1, as follows: The inverse quantized residual Q -1 (Q(r i,j )) is added to the intra block prediction value to produce the reconstructed sample value. The predicted quantized residual value is converted to Sent to the decoder. For lossless codec, if slice_ts_residual_coding_disabled_flag is set to 1, the quantized residual values ​​are sent to the decoder using the conventional transform residual codec as described in 2.2.2. For MPM modes for future intra-mode codecs, if the BDPCM prediction direction is horizontal or vertical, respectively, the horizontal or vertical prediction mode is stored for the BDPCM-coded CU, respectively. For deblocking, if the two blocks on both sides of the block boundary are coded and decoded using BDPCM, then the specific block boundary is not deblocked. 2.1.3 Residual Codec for Transform Skip Mode VVC allows transform skip mode for luma blocks of size up to MaxTsSize×MaxTsSize, where the value of MaxTsSize is signaled in the PPS and can be at most 32. When a CU is encoded and decoded in transform skip mode, its prediction residual is quantized and encoded using the transform skip residual encoding and decoding process. This process is modified from the transform coefficient encoding and decoding process described in 2.2.2. In transform skip mode, the residual of the TU is also encoded and decoded in units of non-overlapping sub-blocks of size 4×4. For better coding efficiency, some modifications are made to customize the residual coding and decoding process to the residual signal characteristics. The following summarizes the differences between transform skip residual coding and conventional transform residual coding: - A forward scan order is applied to scan sub-blocks within a transformed block and also scan positions within the sub-blocks; – no signaling of the final (x, y) position; – When all previous flags are equal to 0, coded_sub_block_flag is coded and decoded for each sub-block except the last sub-block; –sig_coeff_flag context modeling uses a simplified template, and the context model of sig_coeff_flag depends on the top and left neighboring values; – The context model of the abs_level_gt1 flag also depends on the left sig_coeff_flag value and the upper sig_co-eff_flag value; – par_level_flag to use only one context model; – signaling additional greater than 3, 5, 7, 9 flags to indicate coefficient levels, with one context for each flag; – Binarization for the remainder values ​​derived using Rice parameters with fixed order = 1; - Determine the context model for the sign flag based on the left and above neighboring values, and parse the sign flag after sig_coeff_flag to keep all context-coded bins together. For each subblock, if coded_subblock_flag is equal to 1 (i.e., there is at least one non-zero quantized residual in the subblock), encoding and decoding of the quantized residual level is performed in three scanning passes (see Figure 5 ): - First scan pass: Encode and decode the validity flag (sig_coeff_flag), the sign flag (coeff_sign_flag), the flag that the absolute level is greater than 1 (abs_level_gtx_flag[0]), and the parity check (par_level_flag). For a given scan position, if sig_coeff_flag is equal to 1, coeff_sign_flag is encoded and decoded, followed by abs_level_gtx_flag[0] (which specifies whether the absolute level is greater than 1). If abs_level_gtx_flag[0] is equal to 1, par_level_flag is additionally encoded and decoded to specify the parity of the absolute level. – Scan pass greater than x: For each scan position where the absolute level is greater than 1, up to four abs_level_gtx_flag[i] are encoded for i=1..4 to indicate whether the absolute level at the given position is greater than 3, 5, 7 or 9. – Remainder scan pass: The absolute level remainder abs_remainder is encoded and decoded in bypass mode. The absolute level remainder is binarized using a fixed Rice parameter value of 1. The binary bits in scan passes #1 and #2 (the first scan pass and greater than x scan passes) are context-coded until the maximum number of context-coded binary bits in the TU has been exhausted. The maximum number of context-coded binary bits in the residual block is limited to 1.75*block_width*block_height, or equivalently, an average of 1.75 context-coded binary bits per sample position. The binary bits in the last scan pass (remainder scan pass) are bypass-coded. The variable RemCbs is first set to the maximum number of context-coded binary bits for the block and is reduced by 1 each time a context-coded binary bit is coded. When RemCcbs is greater than or equal to 4, the context-coded binary bits are used to encode and decode the syntax elements in the first codec pass, including sig_coeff_flag, coeff_sign_flag, abs_level_gt1_flag, and par_level_flag. If RemCcbs becomes smaller than 4 when encoding and decoding the first pass, the remaining coefficients that have not been encoded in the first pass are encoded and decoded in the remainder scanning pass (pass#3). After the first pass of encoding and decoding is completed, if RemCcbs is greater than or equal to 4, the context-coded binary bits are used to encode and decode the syntax elements in the second pass of encoding and decoding, including abs_level_gt3_flag, abs_level_gt5_flag, abs_level_gt7_flag, and abs_level_gt9_flag. If RemCcbs becomes less than 4 when encoding and decoding the second pass, the remaining coefficients that have not been encoded and decoded in the second pass are encoded and decoded in the remainder scan pass (pass#3). Figure 5 The transform skip residual coding process is shown. The stars mark the positions where the context coded bins are exhausted, at which point all remaining bins are coded using bypass coding. In addition, for blocks not coded in BDPCM mode, a horizontal mapping mechanism is applied to transform skipped residual coding until the maximum number of context-coded binary bits has been reached. Horizontal mapping uses the top and left neighboring coefficient levels to predict the current coefficient level in order to reduce signaling costs. For a given residual position, denote absCoeff as the absolute coefficient level before mapping, and absCoeffMod as the coefficient level after mapping. Let X0 denote the absolute coefficient level of the left neighboring position, and let X1 denote the absolute coefficient level of the upper neighboring position. Horizontal mapping is performed as follows: The absCoeffMod value is then encoded as described above.After all context-decoded bins have been exhausted, horizontal mapping is disabled for all remaining scan positions in the current block. 2.1.4 Palette Mode In VVC, palette mode is used for picture content encoding and decoding in all chroma formats supported in 4:4:4 profile (i.e., 4:4:4, 4:2:0, 4:2:2, and monochrome). When palette mode is enabled, if the CU size is less than or equal to 64×64, a flag is transmitted at the CU level, and the number of samples in the CU is greater than 16 to indicate whether palette mode is used. Considering that applying palette mode on small CUs introduces insignificant codec gain and brings additional complexity on small blocks, palette mode is disabled for CUs less than or equal to 16 samples. A palette-encoded codec unit (CU) is treated as a prediction mode different from intra-prediction, inter-prediction, and intra-block copy (IBC) modes. If palette mode is used, the sample values ​​in a CU are represented by a set of representative color values. This set is called a palette. For positions with sample values ​​close to the palette colors, the palette index is signaled. Samples outside the palette can also be specified by signaling escape symbols. For samples within a CU coded and decoded using escape symbols, their component values ​​are signaled directly using (possibly) quantized component values. This is done in Figure 6 The quantized escaped symbols are binarized using a fifth-order exponential Golomb binarization process (EG5). For palette encoding and decoding, the palette predictor is maintained. For the non-wavefront case, the palette predictor is initialized to 0 at the beginning of each stripe. For the WPP case, the palette predictor at the beginning of each CTU row is initialized to the predictor derived from the first CTU in the previous CTU row, so that the initialization scheme between the palette predictor and CABAC synchronization is unified. For each entry in the palette predictor, a reuse flag is signaled to indicate whether it is part of the current palette in the CU. The reuse flag is sent using a run length codec of zero. Thereafter, the number of new palette entries and the component values ​​of the new palette entries are signaled. After encoding the palette-encoded CU, the palette predictor will be updated with the current palette, and entries from the previous palette predictor that are not reused in the current palette will be added to the end of the new palette predictor until the maximum allowed size is reached. An escape flag is signaled for each CU to indicate whether there is an escape symbol in the current CU. If there is an escape symbol, the palette table is expanded by one and the last index is assigned as the escape symbol. In a manner similar to the coefficient groups (CGs) used in transform coefficient coding, a CU coded with palette mode is divided into multiple line-based coefficient groups, each consisting of m samples (i.e., m=16), where the index run of the escape mode, the palette index value, and the quantized color are encoded / parsed sequentially for each CG. As in HEVC, horizontal or vertical traversal scanning can be applied to scan samples, such as Figure 7 as shown in . The encoding and decoding order for the palette run encoding and decoding in each fragment is as follows: For each sample position, a context encoded binary bit run_copy_flag=0 is signaled to indicate whether the pixel has the same mode as the previous sample position, that is, whether the previously scanned sample and the current sample are both of run type COPY_ABOVE, or whether the previously scanned sample and the current sample both have run type INDEX and the same index value. Otherwise, run_copy_flag=1 is signaled. If the current sample has a different mode from the previous sample, then a context encoded binary bit copy_above_palette_indices_flag is signaled to indicate the run type of the current sample, that is, INDEX or COPY_ABOVE. Here, if the sample is in the first row (horizontal traversal scan) or the first column (vertical traversal scan), the decoder does not have to parse the run type because the INDEX mode is used by default. In the same way, if the previously parsed run type is COPY_ABOVE, the decoder does not have to parse the run type. After palette run encoding of samples in one encoding pass, index values ​​(for INDEX mode) and quantized escape colors are grouped and encoded using CABAC bypass encoding in another encoding pass. This separation of context encoding binary bits and bypass encoding binary bits can improve throughput within each line CG. For slices with dual luma / chroma trees, the palette is applied separately to luma (Y component) and chroma (Cb and Cr components), where the luma palette entries contain only Y values, and the chroma palette entries contain both Cb and Cr values. For slices of a single tree, the palette is applied jointly on the Y, Cb, Cr components, i.e., each entry in the palette contains Y, Cb, Cr values, unless when a CU is encoded using local dual-tree encoding, in which case the encoding of luma and chroma is handled separately. In this case, if the corresponding luma blocks or chroma blocks are encoded using palette mode, their palettes are applied in a manner similar to the dual-tree case (this is relevant for non-4:4:4 codecs and will be further explained in 2.1.4.1). For slices decoded with dual-tree codec, the maximum palette predictor size is 63, and the maximum palette table size for the codec of the current CU is 31. For slices decoded with dual-tree codec, the maximum predictor and palette table sizes are halved, i.e., for each of the luma palette and chroma palette, the maximum predictor size is 31 and the maximum table size is 15. For deblocking, palette-coded blocks on the side of a block boundary are not deblocked. 2.1.4.1 Palette Mode for Non-4:4:4 Content The palette modes in VVC are supported for all chroma formats in a similar manner as the palette modes in HEVC SCC. For non-4:4:4 content, the following customizations apply: 1. When signaling an escape value for a given sample position, if that sample position has only a luma component but no chroma components due to chroma subsampling, then only the luma escape value is signaled. This is the same as in HEVCSCC. 2. For a local dual-tree block, the palette pattern is applied to the block in the same way as the palette pattern applied to a single T-shaped block with two exceptions: a. The process of palette predictor update is slightly modified as follows. Since the local dual-tree block contains only luma (or chroma) components, the predictor update process uses the signaled value of the luma (or chroma) component and fills in the "missing" chroma (or luma) component by setting it to a default value (1<<(component bit depth - 1)). b. The maximum palette predictor size remains at 63 (because the slices are encoded and decoded using a single tree), but the maximum palette table size for luma / chroma blocks remains at 15 (because the blocks are encoded and decoded using separate palettes). 3. For palette mode in monochrome format, the number of color components in a palette-encoded block is set to 1 instead of 3. 2.1.4.2 Encoder Algorithm for Palette Mode On the encoder side, the following steps are used to generate the palette table of the current CU. 1. First, in order to derive the initial entries in the palette table of the current CU, a simplified K-means clustering is applied. The palette table of the current CU is initialized to an empty table. For each sample position in the CU, the SAD between this sample and each palette table entry is calculated, and the minimum SAD among all palette table entries is obtained. If the minimum SAD is less than the predefined error limit errorLimit, the current sample is clustered with the palette table entry with the minimum SAD. Otherwise, a new palette table entry is created. The threshold errorLimit is QP-related and is retrieved from a lookup table containing 57 elements covering the entire QP range. After all samples of the current CU have been processed, the initial palette entries are sorted according to the number of samples clustered with each palette entry, and any entries after the 31st entry are discarded. 2. In the second step, the initial palette table colors are adjusted by considering two options: using the centroid of each cluster from step 1 or using one of the palette colors in the palette predictor. The option with the lower rate-distortion cost is selected as the final color of the palette table. If a cluster has only a single sample and the corresponding palette entry is not in the palette predictor, the corresponding sample is converted to an escape symbol in the next step. 3. The palette table thus generated contains some new entries from the centroids of the clusters in step 1, and some entries from the palette predictor. Therefore, the table is reordered again so that all new entries (i.e., centroids) are placed at the beginning of the table, followed by entries from the palette predictor. Given the palette table of the current CU, the encoder selects a palette index for each sample position in the CU. For each sample position, the encoder checks the RD cost of all index values ​​corresponding to the palette table entry, as well as the index representing the escape symbol, and selects the index with the minimum RD cost using the following equation: RD cost = distortion × (isChroma? 0.8:1) + lambda × bypassed coded bits (2-5) After determining the index map for the current CU, each entry in the palette table is checked to see if it is used by at least one sample position in the CU. Any unused palette entry will be removed. After deciding the index map for the current CU, the trellis RD optimization is applied to find the best values ​​of run_copy_flag and run type for each sample position by comparing the RD costs of three options: same as the previously scanned position, run type COPY_ABOVE, or run type INDEX. When calculating the SAD value, the sample values ​​are scaled down to 8 bits unless the CU is encoded or decoded in lossless mode, in which case the actual input bit depth is used to calculate the SAD. In addition, in the case of lossless codecs, only the ratio is used in the above rate-distortion optimization step (because lossless codecs do not cause distortion). 2.2 Adaptive Color Transformation In the HEVC SCC extension, Adaptive Color Transform (ACT) is applied to reduce the redundancy between the three color components in the 444 chroma format. ACT is also adopted in the VVC standard to enhance the codec efficiency of the 444 chroma format codec. As in HEVC SCC, ACT performs an in-loop color space conversion in the prediction residual domain by adaptively converting the residual from the input color space to the YCgCo space. Figure 8A decoding flow chart for applying ACT is shown. Two color spaces are adaptively selected by signaling an ACT flag at the CU level. When the flag is equal to 1, the residual of the CU is encoded and decoded in the YCgCo space; otherwise, the residual of the CU is encoded and decoded in the original color space. In addition, similar to the HEVC ACT design, for inter and IBc CUs, ACT is enabled only when there is at least one non-zero coefficient in the CU. ACT is only enabled when the chroma component selects the same intra prediction mode of the luminance component (i.e., DM mode). 2.2.1.1ACT Mode In the HEVC SCC extension, ACT supports both lossless and lossy codecs based on the lossless flag (i.e., cu_transquant_bypass_flag). However, there is no flag in the bitstream to indicate whether lossy or lossless codec is applied. Therefore, the YCgCo-R transform is applied as ACT to support both lossy and lossless cases. The YCgCo-R reversible color transform is shown below. Since the YCgCo-R transform is not normalized. In order to compensate for the dynamic range change of the residual signal before and after the color transform, the QP adjustment of (-5, 1, 3) is applied to the transform residuals of the Y, Cg and Co components respectively. The adjusted quantization parameter only affects the quantization and inverse quantization of the residual in the CU. For other encoding and decoding processes (such as deblocking), the original QP is still applied. Additionally, because the forward and inverse color transforms require access to the residuals of all three components, ACT mode is always disabled for single tree partitioning and ISP mode, where the prediction block sizes for different color components are different. When ACT is applied, transform skip (TS) and block differential pulse codec modulation (BDPCM) extended to code chroma residuals are also enabled. 2.2.1.2 ACT Fast Encoding Algorithm To avoid brute force RD searches in both the original and converted color spaces, the following fast encoding algorithm is applied in the VTM reference software to reduce encoder complexity when ACT is enabled. – The order of RD checking for enabling / disabling ACT depends on the original color space of the input video. For RGB video, RD cost for ACT mode is checked first; for YCbCr video, RD cost for non-ACT mode is checked first. RD cost for the second color space is checked only if there is at least one non-zero coefficient in the first color space. – When a CU is obtained through different partitioning paths, the same ACT enable / disable decision is reused. Specifically, when the CU is encoded and decoded for the first time, the selected color space used to encode and decode the residual of a CU will be stored. Then, when the same CU is obtained by another partitioning path, instead of checking the RD cost of the two spaces, the stored color space decision will be reused directly. – The RD cost of the parent CU is used to decide whether to check the RD cost of the second color space of the current CU. For example, if the RD cost of the first color space is less than the RD cost of the second color space for the parent CU, the second color space is not checked for the current CU. – To reduce the number of tested codec modes, the selected codec modes are shared between the two color spaces. Specifically, for intra mode, the pre-selected intra mode candidates according to SATD-based intra mode selection are shared between the two color spaces. For inter and IBC modes, only one block vector search or motion estimation is performed. Block vectors and motion vectors are shared by both color spaces. 2.2.2 Intra-frame template matching Intra Template Matching Prediction (Intra TMP) is a special intra prediction mode that copies the best prediction block from the reconstructed part of the current frame, whose L-shaped template matches the current template. For a predefined search range, the encoder searches for the template that is most similar to the current template in the reconstructed part of the current frame and uses the corresponding block as the prediction block. The encoder then signals the use of this mode and performs the same prediction operation on the decoder side. By combining the L-shaped causal neighbors of the current block with Fig. 9 The prediction signal is generated by matching another block in a predefined search area in the image to generate a prediction signal, the predefined search area including: R1: current CTU; R2: upper left CTU; R3: above CTU; R4: Left CTU. SAD is used as the cost function. In each region, the decoder searches for the template with the minimum SAD relative to the current region and uses its corresponding block as the prediction block. The size of all regions (SearchRange_w, SearchRange_h) is proportional to the block size (BlkW, BlkH) with a fixed number of SAD comparisons per pixel. That is: SearchRange_w=a*BlkW SearchRange_h=a*BlkH Where 'a' is a constant that controls the gain / complexity tradeoff. In practice, 'a' is equal to 5. The intra template matching tool is enabled on width and height for CUs of size less than or equal to 64. This maximum CU size for intra template matching is configurable. When DIMD is not used for the current CU, the intra template matching prediction mode is signaled at the CU level through a dedicated flag. 2.3 Sample Reordering 2.3.1 Reordering of Reconstructed Samples The detailed solutions below should be considered as examples to explain the general concept. These solutions should not be interpreted in a narrow sense. In addition, these solutions can be combined in any way. In the following disclosure, a block may refer to a codec block (CB), a codec unit (CU), a prediction block (PB), a prediction unit (PU), a transform block (TB), a transform unit (TU), a sub-block, a sub-CU, a codec tree unit (CTU), a codec tree block (CTB), or a codec group (CG). In the following disclosure, a region may refer to any video unit, such as a picture, a slice, or a block. A region may also refer to a non-rectangular area, such as a triangle. In the following disclosure, W and H represent the width and height of the rectangular area mentioned. 1. It is proposed that samples in a region can be reordered. a. The reordering of samples can be defined as follows: Assume that the sample at position (x, y) in the region before reordering is denoted as S(x, y), and the sample at position (x, y) in the region after reordering is denoted as R(x, y). It is required that R(x, y) = S(f(x, y), g(x, y)), where (f(x, y), g(x, y)) is the position in the region, and f and g are two functions. i. For example, it is required that there exists at least one position (x, y) such that ((x, y), g(x, y)) is not equal to (x, y). b. The samples in the area to be reordered can be: i. The original sample before encoding; ii. Prediction sample; iii. Reconstruct the sample; iv. Transformed samples (transformation coefficients); v. Samples before inverse transformation (coefficients before inverse transformation); vi. Samples before deblocking filtering; vii. Samples after deblocking filtering; viii. Samples before SAO processing; ix. Samples after SAO processing; x. Samples before ALF processing; xi. Samples after ALF processing; xii. Samples before post-processing; xiii. Samples after post-processing. c. In one example, reordering may be applied in more than one stage. i. For example, at least two of the samples listed in item 1.b above may be reordered. 1) For example, different re-ranking methods can be applied to the two samples. 2) For example, the same re-ranking method can be applied to both samples. d. In one example, the reordering may be a horizontal flip. For example, f(x, y) = Px, g(x, y) = y. For example, P = W-1. e. In one example, the reordering may be a vertical flip. For example, f(x, y) = x, g(x, y) = Qy. For example, Q = H-1. f. In one example, the reordering may be a horizontal-vertical flip. For example, f(x, y) = Px, g(x, y) = Qy. For example, P = W-1 and Q = H-1. g. In one example, the reordering may be a shift. For example, f(x, y) = (P + x) % W, g(x, y) = (Q + y) % H, where P and Q are integers. h. In one example, the reordering may be a rotation. i. In one example, there exists at least one (x, y) such that (x, y) is equal to (f(x, y), g(x, y)). j. In one example, whether and / or how to reorder samples can be signaled from the encoder to the decoder, e.g., in the SPS / sequence header / PPS / picture header / APS / slice header / sub-picture / tile / CTU line / CTU / CU / PU / TU. i. For example, a first flag is signaled to indicate whether reordering is applied. 1) For example, the first flag may be encoded and decoded using context encoding and decoding. ii. For example, a second syntax element (eg, a flag) is signaled to indicate which reordering method (eg, horizontal flip or vertical flip) is used. 1) For example, the second syntax element is signaled only if it is indicated that reordering is applied. 2) For example, context coding may be used to codec the second syntax element. 2. Propose whether and / or how to reorder samples may depend on codec information. a. In one example, whether and / or how to reorder samples may be derived depending on codec information at picture level / slice level / CTU level / CU level / PU level / TU level. b. In one example, the codec information may include: i. The size of the area. ii. The codec mode of the region (e.g., inter, intra, or IBC). iii. Motion information (such as motion vectors and reference indices). iv. Intra prediction mode (eg angular intra prediction mode, planar or DC). v. Inter prediction modes (such as affine prediction, bi-directional prediction / uni-directional prediction, merge mode, combined inter-intra prediction (CIIP), merge with motion vector difference (MMVD), temporal motion vector prediction (TMVP), sub-TMVP). vi. Quantization parameter (QP). vii. Codec tree segmentation information such as codec tree depth. viii. Color format and / or color components. 3. It is proposed that at least one parsing or decoding process other than the reordering process may depend on whether and / or how the samples are reordered. a. For example, a syntax element may be conditionally signaled based on whether or not reordering is applied. b. For example, different scan orders may be used based on whether and / or how the samples are reordered. c. For example, deblocking filtering may be used based on whether and / or how samples are reordered / SAO / ALF. 4. In one example, the samples may be processed by at least one auxiliary process before or after the resampling process. Some possible auxiliary processes may include: (combinations may be allowed) a. For example, at least one sample may be added by an offset. b. For example, at least one sample may be multiplied by a factor. c. For example, at least one sample may be cropped. d. For example, at least one sample may be filtered. e. For example, at least one sample X can be modified to T(X), where T is a function. 5. In one example, for a block encoded and decoded in IBC mode a. For example, a first flag is signaled to indicate whether the reconstructed samples should be reordered. i. For example, the first flag may be encoded and decoded using context encoding and decoding. b. For example, a second flag may be signaled to indicate whether the reconstructed samples should be flipped horizontally or vertically. i. For example, the second flag is signaled only when the first flag is true. ii. For example, the second flag may be encoded and decoded using context encoding and decoding. 2.3.2 Sample Reordering - Application Conditions and Interaction with Other Processes The detailed solutions below should be considered as examples to explain the general concept. These solutions should not be interpreted in a narrow sense. In addition, these solutions can be combined in any way. The term “video unit” or “codec unit” may refer to a picture, a slice, a tile, a codec tree block (CTB), a codec tree unit (CTU), a codec block (CB), a CU, a PU, a TU, a PB, a TB. The term "block" may refer to a codec tree block (CTB), a codec tree unit (CTU), a codec block (CB), a CU, a PU, a TU, a PB, a TB. Note that the terms mentioned below are not limited to the specific terms defined in existing standards. Any changes in encoding tools are also applicable. 1. Regarding the application conditions of sample reordering (e.g., the first problem and related problems), the following method is proposed: a. Whether the reordering process is applied to the reconstructed / original / prediction block may depend on the coded information of the video unit. a. For example, it may depend on the prediction method. b. For example, if the video unit is encoded with one or more modes / techniques listed below, then the reordering process may be applied to the video unit. Otherwise, the reordering process is disabled. i. Intra-block copy (also called IBC). ii. Current Picture Reference (also called CPR). iii. Intra-template matching (also called Intra-TM). iv. IBC template matching (or IBC mode based on template matching). v. Merge-based encoding and decoding. vi. Codec based on AMVP. c. For example, it may depend on the block dimensions (such as block width and / or height). d. For example, if the dimensions W×H of the video unit meet one or more of the rules listed below, then the reordering process may be applied to the video unit. Otherwise, the reordering process is disabled. i. If W>=T1 and / or H>=T2. ii. If W <= T1 and / or H <= T2. iii. If W>T1 and / or H>T2. iv. If W<T1 and / or H<T2. v.If W×H>=T. vi. If W×H>T. vii. If W×H<=T. viii.If W×H<T. 2. Regarding which kinds of samples are reordered and the interaction with other processes (e.g., the second question and related questions), the following methods are proposed: a. A possible sample reordering method can refer to one or more of the following processes: a. The shaped domain samples of the video unit (eg, obtained based on the LMCS method) may be reordered. i. For example, the shaped domain luma samples of a video unit (eg, obtained by luma mapping based on the LMCS method) may be reordered. b. The original domain (rather than the LMCS reshaped domain) samples of the video unit can be reordered. i. For example, the original domain chroma samples of a video unit may be reordered. ii. For example, the original domain luma samples of a video unit may be reordered. c. The reconstructed samples of the video unit can be reordered. i. For example, the reconstructed samples of a video unit may be reordered immediately after adding the decoded residual to the prediction. ii. For example, the integer-domain luma reconstruction samples of a video unit may be reordered. iii. For example, the raw domain luma reconstruction samples of a video unit may be reordered. iv. For example, the original domain chroma reconstructed samples of a video unit may be reordered. d. The inverse brightness mapping of the LMCS process may be applied based on the reordered reconstructed samples. e. A loop filtering process (eg, luma / chroma bilateral filter, luma / chroma SAO, CCSAO, luma / chroma ALF, CCALF, etc.) may be applied based on the reordered reconstructed samples. i. For example, the loop filter process may be applied based on reconstructed samples reordered in the original domain (rather than the LMCS shaping domain). f. Distortion calculations (eg, SSE calculations between original samples and reconstructed samples) may be based on the reordered reconstructed samples. i. For example, the distortion calculation can be based on the reconstructed samples reordered from the original domain. g. The original samples of a video unit can be reordered. i. For example, the integer-domain raw luma samples of a video unit may be reordered. ii. For example, the original domain raw luma samples of a video unit may be reordered. iii. For example, the original domain raw chroma samples of a video unit may be reordered. iv. For example, the residual can be generated by subtracting the prediction from the reordered original samples. h. The prediction samples of the video unit can be reordered. i. For example, the reordering process for prediction samples may be performed immediately after the motion compensation process. ii. For example, sign prediction may be applied based on the reordered prediction samples of the video unit. General Aspects 3. Whether and / or how to apply the method disclosed above may be signaled at the sequence level / picture group level / picture level / slice level / tile group level, for example in the sequence header / picture header / SPS / VPS / DPS / DCI / PPS / APS / slice header / tile group header. 4. Whether and / or how to apply the above disclosed methods can be signaled in PB / TB / CB / PU / TU / CU / VPDU / CTU / CTU row / slice / tile / sub-picture / other kinds of areas containing more than one sample or pixel. 5. Whether and / or how to apply the above disclosed method may depend on the coded information, such as block size, color format, single tree / dual tree partitioning, color component, slice / picture type. 2.3.3 Sample Reordering - Sample Reordering, Signaling and Storage The detailed solutions below should be considered as examples to explain the general concept. These solutions should not be interpreted in a narrow way. In addition, these solutions can be combined in any way. The term “video unit” or “codec unit” may refer to a picture, a slice, a tile, a codec tree block (CTB), a codec tree unit (CTU), a codec block (CB), a CU, a PU, a TU, a PB, a TB. The term "block" may refer to a codec tree block (CTB), a codec tree unit (CTU), a codec block (CB), a CU, a PU, a TU, a PB, a TB. Note that the terms mentioned below are not limited to the specific terms defined in existing standards. Any changes in encoding tools are also applicable. 1. Regarding the signaling of sample reordering (e.g., the first problem and related problems), the following method is proposed: a. For example, at least one new syntax element (e.g., flag, index, variable, parameter, etc.) may be signaled Use of sample reordering to specify video units. a. For example, assuming a particular prediction method is used for a video unit, at least one new syntax element (eg, a flag) may be further signaled to specify the use of sample reordering. b. For example, assuming that the intra template matching usage flag specifies that the video unit is coded by intra template matching, a first new syntax element (eg, a flag) may be further signaled to specify the use of sample reordering for the video unit coded by intra template matching. c. For example, assuming that the IBC amvp flag specifies that the video unit is coded by IBC amvp, a first new syntax element (eg, a flag) may be further signaled to specify the use of sample reordering for the video unit coded by IBC amvp. d. For example, assuming that the IBC merge flag specifies that the video unit is coded by IBC merge, a first new syntax element (eg, a flag) may be further signaled to specify the use of sample reordering for the IBC merge coded video unit. b. In addition, for example, if the first new syntax element specifies that sample reordering is used for a video unit encoded and decoded by a specific prediction method, a second new syntax element (e.g., a flag) may be further signaled to specify which reordering method (e.g., horizontal flipping or vertical flipping) is used for the video unit. c. For example, a single new syntax element (e.g., parameter or variable or index) may be signaled to a video unit, rather than multiple concatenated syntax elements, specifying the type of reordering applied to the video unit (e.g., no flip, horizontal flip, or vertical flip). a. For example, assuming that the intra template matching usage flag specifies that the video unit is encoded and decoded by intra template matching, a new syntax element (e.g., index) can be further signaled to specify the type of reordering of samples of the video unit encoded and decoded by intra template matching. b. For example, assuming that the IBC amvp flag specifies that the video unit is coded by IBC amvp, a new syntax element (eg, index) may be further signaled to specify the type of sample reordering for the video unit coded by IBC amvp. c. For example, assuming that the IBC merge flag specifies that the video unit is coded by IBC merge, a new syntax element (eg, index) may be further signaled to specify the type of sample reordering for the video unit coded by IBC merge. d. Additionally, for example, a new syntax element (eg, index) equal to 0 specifies that sample reordering is not used; equal to 1 specifies that sample reordering method A is used; equal to 2 specifies that sample reordering method B is used; and so on. d. For example, one or more syntax elements related to sample reordering may be context encoded and decoded. a. For example, the context may be based on neighboring block / sample coding information (eg, availability, prediction mode, whether merge coded, whether IBC coded, whether sample reordering is applied, which sample reordering method is used, etc.). e. Alternatively, for example, instead of signaling whether to perform sample reordering and / or which reordering method to use for a video unit, some (or all) of these steps may be determined based on predefined rules (without signaling). a. For example, the predefined rules may be based on information about neighboring block / sample codecs. b. For example, assuming that the IBC merge flag specifies that the video unit is encoded and decoded via IBC merging, a process may be performed to determine whether and how to perform reordering based on predefined rules / processes. i. Alternatively, for example, assume that the first new syntax element specifies sample reordering for a video unit, however, instead of further signaling the reordering method, how to reorder is determined based on a predefined rule / procedure (no signaling). ii. Alternatively, for example, whether to perform reordering may be determined implicitly based on a predefined rule / process, but how to reorder may be signaled. c. For example, assuming that the IBC amvp flag specifies that the video unit is coded by IBC amvp, a process can be performed to determine whether and how to perform reordering based on predefined rules / processes. i. Alternatively, for example, assuming that the first new syntax element specifies sample reordering for a video unit, however, instead of further signaling the reordering method, how can the reordering be performed based on a predefined rule / procedure (without signaling) to determine how to reorder. ii. Alternatively, for example, whether to perform reordering may be determined implicitly based on a predefined rule / process, but how to reorder may be signaled. d. For example, assuming that the intra template matching flag specifies that the video unit is encoded by IBC merging, a process can be performed to determine whether and how to perform reordering based on predefined rules / processes. i. Alternatively, for example, assuming that the first new syntax element specifies sample reordering for a video unit, however, instead of further signaling the reordering method, how can the reordering be performed based on a predefined rule / procedure (without signaling) to determine how to reorder. ii. Alternatively, for example, whether to perform reordering may be determined implicitly based on a predefined rule / process, but how to reorder may be signaled. f. For example, whether to perform reordering and / or how to reorder can be inherited from the encoded and decoded blocks. a. For example, it may be inherited from an adjacent spatially neighboring block. b. For example, it may be inherited from a non-adjacent spatially neighboring block. c. For example, it may be inherited from a history-based motion table such as some HMVP table. d. For example, it may be inherited from the temporal motion candidate. e. For example, it can be inherited based on the IBC merge candidate list. f. For example, it can be inherited based on the IBC amvp candidate list. g. For example, it can be inherited based on a generated motion candidate list / table. h. For example, in case a video unit is encoded and decoded via IBC merge mode, sample reordering inheritance may be allowed. i. For example, in case a video unit is encoded and decoded by IBC AMVP mode, sample reordering inheritance may be allowed. j. For example, in the case where a video unit is encoded and decoded via intra template matching mode, sample reordering inheritance may be allowed. 2. With regard to the storage of sample reordering states (e.g., second and related issues), the following method is proposed: a. For example, information on whether and / or how to reorder video units may be stored. a. For example, the stored information can be used for encoding and decoding of future video units. b. For example, this information may be stored in a buffer. i. For example, a buffer can be a line buffer, a table, more than one line buffer, a picture buffer, a compressed picture buffer, a temporal buffer, etc. c. For example, this information may be stored in a historical motion vector table (such as a HMVP table). b. For example, coding information (e.g., whether sample reordering is applied, which sample reordering method is used, block availability, prediction mode, whether merge coded or IBC coded, etc.) may be stored for deriving the context of the sample reordering syntax element. General Aspects 3. Whether and / or how to apply the method disclosed above can be applied at the sequence level / picture group level / picture level / strip level / Signaled at tile group level, for example in sequence header / picture header / SPS / VPS / DPS / DCI / PPS / APS / slice header / tile group header. 4. Whether and / or how to apply the above disclosed methods can be signaled in PB / TB / CB / PU / TU / CU / VPDU / CTU / CTU row / slice / tile / sub-picture / other kinds of regions containing more than one sample or pixel. 5. Whether and / or how to apply the above disclosed method may depend on the coded information, such as block size, color format, single / dual tree partitioning, color component, slice / picture type. 3 Questions To date, codec tools such as IBC (in VVC and ECM) and intra template matching (in ECM) directly copy the previously coded blocks in the current picture. However, the samples in the reconstructed blocks can be reordered / transformed / flipped / rotated to obtain higher codec gain. The following issues can be considered: 1. Motion candidate list generation for sample re-ranking. 2. Implicit determination of sample reordering. 3. How to reorder samples. 4 Detailed solutions The detailed solutions below should be considered as examples to explain the general concept. These solutions should not be interpreted in a narrow sense. In addition, these solutions can be combined in any way. The term “video unit” or “codec unit” may refer to a picture, a slice, a tile, a codec tree block (CTB), a codec tree unit (CTU), a codec block (CB), a CU, a PU, a TU, a PB, a TB. The term "block" may refer to a codec tree block (CTB), a codec tree unit (CTU), a codec block (CB), a CU, a PU, a TU, a PB, a TB. Note that the terms mentioned below are not limited to the specific terms defined in existing standards. Any changes in codec tools are also applicable. 4.1 Regarding motion candidate list generation for sample reordering (eg, the first problem and related problems), the following method is proposed. b. For example, the IBC merge motion candidate list can be used for both the regular IBC merge mode and the sample reordering based IBC merge mode. c. For example, the IBC amvp motion prediction candidate list can be used for both the regular IBC amvp mode and the sample reordering based IBC amvp mode. d. For example, for a target video unit using sample reordering codec, the new motion (prediction) A candidate list is generated. a. For example, the new candidate list may only consider motion candidates that utilize the same reordering method as that of the target video unit. b. For example, the new candidate list may only consider motion candidates that utilize sample reordering codecs (but regardless of the type of sample reordering method). c. Alternatively, a new candidate list may be generated without considering the sample reordering method for each motion candidate. d. For example, non-adjacent motion candidates may be inserted into a new candidate list. i. For example, non-adjacent candidates utilizing sample reordering (but regardless of the type of sample reordering method) may be inserted. ii. For example, non-adjacent candidates of the same reordering method as that of the target video unit may be inserted. iii. For example, non-adjacent candidates may be inserted regardless of whether a sample re-ranking method is applied to the candidates. e. For example, new motion candidates may be generated according to certain rules and inserted into the new candidate list. i. For example, the rules can be based on an averaging process. ii. For example, the rules can be based on the editing process. iii. For example, the rules can be based on a scaling process. e. For example, the motion (prediction) candidate list generation for the target video unit may depend on the reordering method. a. For example, the reordering method associated with each motion candidate (from spatial or temporal domain or history table) may be inserted into the list, whether the target video unit will be encoded or decoded with sample reordering. b. For example, if the target video unit is to be encoded with sample reordering, only those motion candidates (from spatial or temporal domain or history table) that are encoded with the same reordering method as that of the target video unit are inserted into the list. c. For example, if the target video unit is to be coded with sample reordering, only those motion candidates (from the spatial domain or the temporal domain or the history table) that are coded with sample reordering are inserted into the list. d. For example, if the target video unit is not coded using sample reordering, those motion candidates (from the spatial domain or temporal domain or the history table) coded using the same reordering method may not be inserted into the list. e. Alternatively, the generation of a motion list for a video unit may not depend on the reordering method associated with each motion candidate. f. For example, adaptive reordering of merge candidates (ARMC) of video units may depend on the reordering method. a. For example, if the target video unit is to be encoded using sample reordering, motion candidates encoded using the same reordering method as that of the target video unit may be placed before those motion candidates encoded using a different reordering method. b. For example, if the target video unit is to be encoded with sample reordering, motion candidates encoded with sample reordering (but regardless of the type of sample reordering method) may be placed before those motion candidates encoded with a different reordering method. c. For example, if the target video unit is encoded without sample reordering, motion candidates that are encoded without the reordering method may be placed before those motion candidates that are encoded with the reordering method. d. Alternatively, ARMC may be applied to video units regardless of the reordering method associated with each motion candidate. 4.2 Regarding the implicit determination of sample reordering (eg, the second problem and related problems), the following method is proposed. a. Whether to reorder the reconstructed / original / predicted samples of a video unit can be implicitly derived from the codec information at both the encoder and the decoder. a. Implicit derivation can be based on cost / error / difference calculated using codec information. i. For example, the cost / error / difference can be calculated based on template matching. ii. For example, template matching can be performed by comparing samples in the first template and the second template. 1. For example, a first template is constructed from a set of predefined samples that are neighbors to the current video unit, and a second template is constructed from a set of corresponding samples that are neighbors to the reference video unit. 2. For example, the cost / error may refer to the cumulative sum of the differences between the samples in the first template and the corresponding samples in the second template. a. For example, the difference may be based on the luma sample values. 3. For example, a sample may refer to a reconstructed sample or a variant based on a reconstructed sample. 4. For example, a sample can refer to a predicted sample or a variant based on a predicted sample. b. For example, the first cost (represented by Cost0) can be calculated without reordering, and the second cost (represented by Cost1) can be calculated by using the ordering. Finally, the minimum cost value among {Cost0, Cost1} is identified, and the corresponding codec method (without reordering or with reordering) is determined as the final codec method of the video unit. c. Alternatively, whether to reorder the reconstructed / original / predicted samples of a video unit may be signaled in the bitstream. i. For example, it can be signaled by a syntax element (eg, a flag). b. Which reordering method to use to reorder the reconstructed / original / prediction samples can be implicitly derived from the codec information at both the encoder and the decoder. a. For example, whether to flip horizontally or vertically. b. Implicit derivation can be based on cost / error / difference calculated using codec information. i. For example, the cost / error / difference can be calculated based on template matching. ii. For example, template matching can be performed by comparing samples in the first and second templates. 1. For example, a first template is constructed from a set of predefined samples that are neighbors to the current video unit, and a second template is constructed from a set of corresponding samples that are neighbors to the reference video unit. 2. For example, the cost / error may refer to the cumulative sum of the differences between the samples in the first template and the corresponding samples in the second template. a. For example, the difference may be based on the luma sample values. 3. For example, a sample may refer to a reconstructed sample or a variant based on a reconstructed sample. 4. For example, a sample can refer to a predicted sample or a variant based on a predicted sample. iii. For example, the first cost (represented by Cost0) may be calculated without using reordering method A, and the second cost (represented by Cost1) may be calculated using reordering method B. Finally, the minimum cost value among {Cost0, Cost1} is identified, and the corresponding codec method (reordering method A, reordering method B) is determined as the final codec method of the video unit. c. Alternatively, which reordering method is used to reorder the reconstructed / original / predicted samples of a video unit can be signaled in the bitstream. i. For example, it may be signaled by a syntax element (eg, a flag, index, parameter or variable). c. Whether or which reordering method to use to reorder the reconstructed / original / prediction samples of a video unit can be implicitly derived from the codec information at both the encoder and the decoder. a. For example, the first cost (represented by Cost0) can be calculated without reordering, the second cost (represented by Cost1) can be calculated using reordering method A; the third cost (represented by Cost2) can be calculated using reordering method B. Finally, the minimum cost value among {Cost0, Cost1, Cost2} is identified, and the corresponding codec method (without reordering, reordering method A, reordering method B) is determined as the final codec method of the video unit. 4.3 Regarding how to reorder samples (eg, the third problem and related problems), the following method is proposed. b. A possible sample reordering method can refer to one or more of the following processes: a. The reordering process can be applied on a video unit basis. i. For example, the reordering process can be based on block / CU / PU / TU. ii. For example, the reordering process may not be tile / slice / picture based. b. Samples of a video unit may be transformed according to an M-parameter model (eg, M=2, 4, 6, or 8). c. Samples of a video unit can be reordered. d. Samples of video units can be rotated. e. The samples of the video unit can be transformed according to the affine model. f. The samples of the video unit can be transformed according to the linear model. g. The samples of the video unit can be transformed according to the projection model. h. The samples of the video unit can be flipped in the horizontal direction. i. The samples of the video unit can be flipped along the vertical direction. General 4.4 Whether and / or how to apply the above disclosed method may be signaled at the sequence level / picture group level / picture level / slice level / tile group level, for example in the sequence header / picture header / SPS / VPS / DPS / DCI / PPS / PPS / slice header / tile group header. 4.5 Whether and / or how the above disclosed methods can be applied in PB / TB / CB / PU / TU / CU / VPDU / CTU / CTU A row / slice / tile / sub-picture / other kind of area containing more than one sample or pixel is signaled. 4.6 Whether and / or how to apply the above disclosed method may depend on codec information, such as block size, color format, single / dual tree partitioning, color component, slice / picture type.

[0072] More details of embodiments of the present disclosure related to sample adjustment will be described below. The embodiments of the present disclosure should be considered as examples to explain general concepts and should not be interpreted in a narrow sense. In addition, these embodiments can be applied individually or in combination in any way.

[0073] As used herein, the term "block" may refer to a codec tree block (CTB), a codec tree unit (CTU), a codec block (CB), a codec unit (CU), a prediction unit (PU), a transform unit (TU), a prediction block (PB), a transform block (TB), a video processing unit including a plurality of samples / pixels, etc. A block may be rectangular or non-rectangular.

[0074] Fig.10 1 shows a flow chart of a method 1000 for video processing according to some embodiments of the present disclosure. The method 1000 may be implemented during a conversion between a current video block of a video and a bitstream of the video. Fig.10 As shown, method 1000 begins at 1002, where a motion candidate list is generated for a current video block. An adjustment process is applied to a plurality of samples of the current video block.

[0075] In some embodiments, the plurality of samples may include reconstructed samples of the current video block, original samples of the current video block, predicted samples of the current video block, etc. Additionally or alternatively, the adjustment process may include reordering the plurality of samples, flipping the plurality of samples, shifting the plurality of samples, rotating the plurality of samples, transforming the plurality of samples, etc. In one example, the plurality of samples may be transformed according to an M parameter model, where M is an integer, such as 2, 4, 6, or 8. Alternatively, the plurality of samples may be transformed according to an affine model, a linear model, a projection model, etc. In another instance, the plurality of samples may be flipped along a horizontal direction or a vertical direction.

[0076] As used herein, information about how to adjust samples of a video block in an adjustment process may also be referred to as an adjustment method, a scheme for an adjustment process, or a type of adjustment process. It should be understood that the above examples are described for illustrative purposes only. The scope of the present disclosure is not limited in this regard.

[0077] In some embodiments, the motion candidate list may be an intra-block copy (IBC) merged motion candidate list for the current video block. That is, the IBC merged motion candidate list may be used for both the conventional IBC merge mode and the IBC merge mode based on sample adjustment. In some alternative embodiments, the motion candidate list may be an IBC advanced motion vector prediction (AMVP) motion candidate list for the current video block. That is, the IBC AMVP motion candidate list may be used for both the conventional IBC AMVP mode and the IBC AMVP mode based on sample adjustment. In other embodiments, the motion candidate list is different from the IBC merged motion candidate list and the IBC AMVP motion candidate list for the current video block, which will be described in detail below.

[0078] At 1004, conversion is performed based on the motion candidate list. In one example, the conversion may include encoding the current video block into a bitstream. Alternatively or additionally, the conversion may include decoding the current video block from the bitstream.

[0079] In view of the above, for a video block, a motion candidate list is generated, whose samples are adjusted based on the adjustment process. Compared with the traditional scheme, the proposed method can advantageously better support sample adjustment, thereby achieving higher coding gain and improving coding efficiency.

[0080] In some embodiments, the motion candidates in the motion candidate list may be selected from spatial motion candidates, temporal motion candidates, a history table, and the like.

[0081] In some embodiments, a motion candidate in a motion candidate list may be selected from a plurality of motion candidates. Samples of each of the plurality of motion candidates may be adjusted in the same manner as a plurality of samples of the current video block. For example, only motion candidates using the same adjustment process scheme as the current video block may be considered to generate the motion candidate list.

[0082] In some embodiments, a motion candidate in a motion candidate list may be selected from a plurality of motion candidates. The adjustment process may be applied to a sample of each motion candidate in the plurality of motion candidates. For example, regardless of the type of the adjustment process (i.e., the scheme of the adjustment process), the motion candidate adjusted using the adjustment process may be considered for generating the motion candidate list.

[0083] In some embodiments, the motion candidate list can be generated independently of the adjustment process. That is, the motion candidate list can be generated without considering whether the adjustment process is applied and how to adjust the samples of the video block.

[0084] In some embodiments, the motion candidate list may include a first motion candidate that is not adjacent to the current video block. In one embodiment, the adjustment process may be applied to the first motion candidate. For example, regardless of the type of the adjustment process (i.e., the scheme of the adjustment process), one or more non-adjacent motion candidates adjusted using the adjustment process may be added to the motion candidate list. In another embodiment, the samples of the first motion candidate may be adjusted in the same manner as the multiple samples of the current video block. For example, only non-adjacent motion candidates using the same adjustment process scheme as the current video block may be added to the motion candidate list. In another embodiment, the first motion candidate may be added to the motion candidate list independently of whether the adjustment process is applied to the samples of the first motion candidate.

[0085] In some embodiments, the motion candidate list may include motion candidates generated according to rules based on an averaging process. In some other embodiments, the motion candidate list may include motion candidates generated according to rules based on a clipping process. Alternatively, the motion candidate list may include motion candidates generated according to rules based on a scaling process. It should be understood that the above examples are described for illustrative purposes only. The scope of the present disclosure is not limited in this regard.

[0086] In some embodiments, based on information about how to adjust the samples of the video block during the adjustment process, another motion candidate list can be generated for another video block of the video. The other video block is different from the current video block. In some embodiments, the other motion candidate list can include information associated with the motion candidates in the other motion candidate list. For example, the adjustment method of the motion candidate can be added to the other motion candidate list. This adjustment method may or may not be considered for subsequent processing. In some embodiments, the adjustment process can be applied to the samples of the other video block.

[0087] In some embodiments, if the adjustment process is applied to samples of another video block, the samples of each motion candidate in another motion candidate list can be adjusted in the same manner as the samples of another video block. For example, only motion candidates that use the same adjustment process scheme as the current video block can be added to another motion candidate list.

[0088] In some embodiments, if the adjustment process is applied to samples of another video block, the adjustment process may be applied to samples of each motion candidate in another motion candidate list. In one example, samples of each motion candidate in another motion candidate list may be adjusted in the same manner as samples of another video block. In another example, samples of motion candidates in another motion candidate list may be adjusted in a different manner than samples of another video block. In other words, regardless of the scheme of the adjustment process, one or more motion candidates adjusted using the adjustment process may be added to another motion candidate list.

[0089] In some embodiments, if the adjustment process is not applied to samples of another video block, the adjustment process is not applied to samples of each motion candidate in another motion candidate list. In other words, the motion candidate adjusted by the adjustment process may not be added to another motion candidate list.

[0090] In some embodiments, another motion candidate list may be generated for another video block of the video independent of information about how samples of the video block are adjusted during the adjustment process.

[0091] In some embodiments, the adaptive reordering (ARMC) of the merge candidate of the other video block may depend on information about how the samples of the video block are adjusted during the adjustment process. In one example, if the adjustment process is applied to the samples of the other video block, the second motion candidate may be before the third motion candidate in the other motion candidate list. That is, the second motion candidate may be placed before the third motion candidate in the other motion candidate list. The samples of the second motion candidate are adjusted in the same manner as the samples of the other video block, and the samples of the third motion candidate are adjusted in a different manner than the samples of the other video block.

[0092] Alternatively, if the adjustment process is applied to samples of another video block, the fourth motion candidate in another motion candidate list may be before the fifth motion candidate. The adjustment process is applied to samples of the fourth motion candidate and is not applied to samples of the fifth motion candidate. In one example, samples of the fourth motion candidate may be adjusted in the same manner as samples of another video block. In another example, samples of the fourth motion candidate may be adjusted in a different manner than samples of another video block. In other words, regardless of the type of adjustment process, motion candidates adjusted using the adjustment process in another motion candidate list may be placed before motion candidates that do not use the adjustment process.

[0093] In some embodiments, if the adjustment process is not applied to samples of another video block, the fifth motion candidate in another motion candidate list may be before the fourth motion candidate. The adjustment process is applied to samples of the fourth motion candidate and not applied to samples of the fifth motion candidate. In other words, the motion candidate in another motion candidate list that does not utilize the adjustment process may be placed before the motion candidate that is adjusted using the adjustment process.

[0094] In some alternative embodiments, adaptive reordering of merge candidates (ARMC) may be applied to another video block independently of information about how the samples of the video block were adjusted in the adjustment process.

[0095] In some embodiments, the adjustment process may be applied based on at least one of: information of a video block of the video, information of a codec unit (CU) of the video, information of a prediction unit (PU) of the video, or information of a transform unit (TU) of the video. For example, a syntax element may be included in the bitstream and indicate that the adjustment process is enabled or disabled for a video block, CU, PU, ​​or TU. Additionally or alternatively, the adjustment process may be applied independently of at least one of: information of a tile of the video, information of a strip of the video, or information of a picture of the video. For example, there will be no syntax element in the bitstream indicating that the adjustment process is enabled or disabled for a video block, CU, PU, ​​or TU.

[0096] In some embodiments, whether and / or how to apply the method may be indicated at a sequence level, a group of picture level, a picture level, a slice level, a tile group level, etc. In some embodiments, whether and / or how to apply the method may be indicated in a sequence header, a picture header, a sequence parameter set (SPS), a video parameter set (VPS), a dependency parameter set (DPS), decoding capability information (DCI), a picture parameter set (PPS), an adaptation parameter set (APS), a slice header, a tile group header, etc.

[0097] In some embodiments, whether and / or how the method is applied may be indicated at an area containing more than one sample or pixel. As an example and not limitation, the area may include a prediction block (PB), a transform block (TB), a codec block (CB), a prediction unit (PU), a transform unit (TU), a codec unit (CU), a virtual pipeline data unit (VPDU), a codec tree unit (CTU), a CTU row, a slice, a tile, a sub-picture, etc.

[0098] In some embodiments, whether and / or how to apply the method may depend on codec information. As an example and not limitation, the codec information may include block size, color format, single-tree partition, double-tree partition, color component, slice type, picture type, etc.

[0099] According to another embodiment of the present disclosure, a non-transitory computer-readable recording medium is provided. The non-transitory computer-readable recording medium stores a bitstream of a video generated by a method performed by a device for video processing. In the method, a motion candidate list is generated for a current video block of the video. The adjustment process is applied to multiple samples of the current video block. In addition, a bitstream is generated based on the motion candidate list.

[0100] According to some other embodiments of the present disclosure, a method for storing a bitstream of a video is provided. In the method, a motion candidate list is generated for a current video block of the video. The adjustment process is applied to multiple samples of the current video block. In addition, the bitstream is generated based on the motion candidate list, and the bitstream is stored in a non-transitory computer-readable recording medium.

[0101] Fig.11 1 shows a flow chart of a method 1100 for video processing according to some embodiments of the present disclosure. The method 1100 may be implemented during a conversion between a current video block of a video and a bitstream of the video. Fig.11 As shown, method 1100 begins at 1102, where cost information associated with an adjustment process for adjusting samples of a video block is determined based on codec information of the video. As used herein, cost information may include a cost determined based on the codec information, an error determined based on the codec information, or a difference determined based on the codec information, etc.

[0102] In some embodiments, the samples may include reconstructed samples of the video block, original samples of the video block, predicted samples of the video block, etc. Additionally or alternatively, the adjustment process may include reordering the samples of the video block, flipping the samples of the video block, shifting the samples of the video block, rotating the samples of the video block, transforming the samples of the video block, etc. In one example, the samples of the video block may be transformed according to an M parameter model, where M is an integer, such as 2, 4, 6, or 8. Alternatively, the samples of the video block may be transformed according to an affine model, a linear model, a projection model, etc. In another example, the samples of the video block may be flipped along the horizontal direction or the vertical direction.

[0103] As used herein, information about how to adjust samples of a video block in an adjustment process may also be referred to as an adjustment method, a scheme of an adjustment process, or a type of an adjustment process. It should be understood that the above examples are described for illustrative purposes only. The scope of the present disclosure is not limited in this regard.

[0104] At 1104, target information about the adjustment process is determined for the current video block based on the cost information. At 1006, conversion is performed based on the target information. In one example, the conversion may include encoding the current video block into a bitstream. Alternatively or additionally, the conversion may include decoding the current video block from the bitstream.

[0105] In view of the above, information about the adjustment process is implicitly determined from the codec information. Compared with the traditional scheme, the proposed method can advantageously better support sample adjustment, thereby achieving higher codec gain and improving codec efficiency.

[0106] In some embodiments, the target information may include how to adjust multiple samples of the current video block. In one example, the target information may include whether to flip multiple samples horizontally or vertically. In another example, the target information may include whether to rotate multiple samples or transform multiple samples according to a model. It should be understood that the above examples are described for illustrative purposes only. The scope of the present disclosure is not limited in this regard.

[0107] As an example and not limitation, the cost information may include costs of multiple schemes for the adjustment process.The target information may indicate that multiple samples of the current video block are adjusted based on a scheme with the least cost among the multiple schemes.

[0108] In some alternative embodiments, the target information may include whether the adjustment process is applied to multiple samples of the current video block. For example, the cost information may include a first cost determined by the adjustment process being applied to the multiple samples and a second cost determined by the adjustment process not being applied to the multiple samples. As an example and not limitation, if the first cost is less than the second cost, the target information may indicate that the adjustment process is applied to the multiple samples. If the first cost is greater than the second cost, the target information may indicate that the adjustment process is not applied to the multiple samples.

[0109] In other embodiments, the target information may include whether the adjustment process is applied to the multiple samples of the current video block and how the multiple samples are adjusted. In this case, the cost information may include, for example, a first cost determined by not applying the adjustment process to the multiple samples, a second cost determined by adjusting the multiple samples based on the first scheme for the adjustment process, and a third cost determined by adjusting the multiple samples based on the second scheme for the adjustment process.

[0110] In some embodiments, if the first cost is less than the second cost and the third cost, the target information may indicate that the adjustment process is not applied to the plurality of samples. If the second cost is less than the first cost and the third cost, the target information may indicate that the plurality of samples of the current video block are adjusted based on the first scheme. If the third cost is less than the first cost and the second cost, the target information may indicate that the plurality of samples of the current video block are adjusted based on the second scheme.

[0111] In some embodiments, the cost information may be determined based on the codec information and the template matching process. As an example and not limitation, the template matching process may be performed by comparing samples in a first template and a second template associated with the current video block. For example, the first template may include samples that are adjacent to the current video block, and the second template may include samples that are adjacent to the reference video block of the current video block. In one example, the cost information may be determined based on the cumulative sum of the differences between the samples in the first template and the corresponding samples in the second template. In another example, the cost information may be determined based on the cumulative sum of the differences between the values ​​of the luminance samples in the first template and the values ​​of the corresponding luminance samples in the second template. Alternatively, the cost information may be determined based on the cumulative sum of the differences between the values ​​of the chrominance samples in the first template and the values ​​of the corresponding chrominance samples in the second template.

[0112] In some embodiments, the samples used to determine the cost information may be reconstructed samples, variations based on reconstructed samples, predicted samples, variations based on predicted samples, and the like.

[0113] In some alternative embodiments, the target information may be indicated in the bitstream. In a non-limiting example, the decoder may obtain the target information from the bitstream without determining the cost information. For example, a syntax element indicating the target information may be included in the bitstream. In one example, the syntax element may be a flag. In another example, the syntax element may be an index. In another example, the syntax element may be a variable. In yet another example, the syntax element may be a parameter. It should be understood that the above examples are described for descriptive purposes only. The scope of the present disclosure is not limited in this respect.

[0114] In some embodiments, the adjustment process is applied based on at least one of: information of a video block of the video, information of a codec unit (CU) of the video, information of a prediction unit (PU) of the video, or information of a transform unit (TU) of the video. For example, a syntax element may be included in the bitstream and indicate that the adjustment process is enabled or disabled for a video block, CU, PU, ​​or TU. Additionally or alternatively, the adjustment process may be applied independently of at least one of: information of a tile of the video, information of a slice of the video, or information of a picture of the video. For example, there will be no syntax element in the bitstream indicating that the adjustment process is enabled or disabled for a video block, CU, PU, ​​or TU.

[0115] In some embodiments, whether and / or how to apply the method may be indicated at a sequence level, a group of picture level, a picture level, a slice level, a tile group level, etc. In some embodiments, whether and / or how to apply the method may be indicated in a sequence header, a picture header, a sequence parameter set (SPS), a video parameter set (VPS), a dependency parameter set (DPS), decoding capability information (DCI), a picture parameter set (PPS), an adaptation parameter set (APS), a slice header, a tile group header, etc.

[0116] In some embodiments, whether and / or how the method is applied may be indicated at an area containing more than one sample or pixel. As an example and not limitation, the area may include a prediction block (PB), a transform block (TB), a codec block (CB), a prediction unit (PU), a transform unit (TU), a codec unit (CU), a virtual pipeline data unit (VPDU), a codec tree unit (CTU), a CTU row, a slice, a tile, a sub-picture, etc.

[0117] In some embodiments, whether and / or how to apply the method may depend on codec information. As an example and not limitation, the codec information may include block size, color format, single-tree partition, double-tree partition, color component, slice type, picture type, etc.

[0118] According to another embodiment of the present disclosure, a non-transitory computer-readable recording medium is provided. The non-transitory computer-readable recording medium stores a bitstream of a video generated by a method performed by a device for video processing. According to the method, based on codec information of the video, cost information associated with an adjustment process is determined, in which samples of a video block are adjusted. Based on the cost information, target information about the adjustment process for a current video block of the video is determined. In addition, a bitstream is generated based on the target information.

[0119] According to some other embodiments of the present disclosure, a method for storing a bitstream of a video is provided. In the method, based on the codec information of the video, cost information associated with an adjustment process is determined, in which samples of a video block are adjusted. Based on the cost information, target information about the adjustment process for a current video block of the video is determined. In addition, a bitstream is generated based on the target information, and the bitstream is stored in a non-transitory computer-readable recording medium.

[0120] Embodiments of the present disclosure may be described according to the following clauses, features of which may be combined in any reasonable way.

[0121] Clause 1. A method for video processing, comprising: for conversion between a current video block of a video and a bitstream of the video, generating a motion candidate list for the current video block, an adjustment process being applied to multiple samples of the current video block; and performing the conversion based on the motion candidate list.

[0122] Clause 2. The method of clause 1, wherein the motion candidate list is different from an intra block copy (IBC) merge motion candidate list and an IBC advanced motion vector prediction (AMVP) motion candidate list for the current video block.

[0123] Clause 3. A method according to any one of clauses 1 to 2, wherein the motion candidates in the motion candidate list are selected from a plurality of motion candidates, and samples of each of the plurality of motion candidates are adjusted in the same manner as the plurality of samples of the current video block.

[0124] Clause 4. A method according to any one of clauses 1 to 2, wherein the motion candidate in the motion candidate list is selected from a plurality of motion candidates, and the adjustment process is applied to samples of each motion candidate in the plurality of motion candidates.

[0125] Clause 5. A method according to any one of clauses 1 to 2, wherein the motion candidate list is generated independently of the adjustment process.

[0126] Clause 6. The method of any one of clauses 1 to 5, wherein the motion candidate list comprises a first motion candidate that is not adjacent to the current video block.

[0127] Clause 7. The method of clause 6, wherein the adjustment process is applied to the first motion candidate.

[0128] Clause 8. The method of any of clauses 6 to 7, wherein samples of the first motion candidate are adjusted in the same manner as the plurality of samples of the current video block.

[0129] Clause 9. The method of clause 6, wherein the first motion candidate is added to the motion candidate list independently of whether the adjustment process is applied to samples of the first motion candidate.

[0130] Clause 10. The method according to any one of clauses 1 to 9, wherein the motion candidate list comprises motion candidates generated according to a rule based on an averaging process, a cropping process or a scaling process.

[0131] Clause 11. The method of clause 1, wherein the motion candidate list is an IBC merge motion candidate list or an IBC AMVP motion candidate list for the current video block.

[0132] Clause 12. A method according to any one of clauses 1 to 11, wherein based on information about how to adjust samples of the video block in the adjustment process, another motion candidate list is generated for another video block of the video, and the other video block is different from the current video block.

[0133] Clause 13. The method of clause 12, wherein the another motion candidate list includes the information associated with the motion candidates in the another motion candidate list.

[0134] Clause 14. The method of clause 13, wherein the adjustment process is applied to samples of the other video block.

[0135] Clause 15. The method of clause 12, wherein if the adjustment process is applied to samples of the other video block, samples of each motion candidate in the other motion candidate list are adjusted in the same manner as the samples of the other video block.

[0136] Clause 16. The method of clause 12, wherein if the adjustment process is applied to samples of the another video block, the adjustment process is applied to samples of each motion candidate in the another motion candidate list.

[0137] Clause 17. The method of clause 16, wherein samples of each motion candidate in the another motion candidate list are adjusted in the same manner as the samples of the another video block.

[0138] Clause 18. The method of clause 16, wherein samples of the motion candidates in the another motion candidate list are adjusted differently than the samples of the another video block.

[0139] Clause 19. The method of clause 12, wherein if the adjustment process is not applied to samples of the another video block, then the adjustment process is not applied to samples of each motion candidate in the another motion candidate list.

[0140] Clause 20. A method according to any one of clauses 1 to 11, wherein independently of information about how samples of a video block are adjusted in the adjustment process, another motion candidate list is generated for another video block of the video, and the other video block is different from the current video block.

[0141] Clause 21. The method of any of clauses 12 to 20, wherein adaptive reordering of merging candidates (ARMC) of the further video block depends on the information.

[0142] Clause 22. A method according to clause 21, wherein if the adjustment process is applied to samples of the other video block, the second motion candidate in the other motion candidate list precedes the third motion candidate, the samples of the second motion candidate are adjusted in the same manner as the samples of the other video block, and the samples of the third motion candidate are adjusted in a different manner from the samples of the other video block.

[0143] Clause 23. A method according to Clause 21, wherein if the adjustment process is applied to samples of the other video block, the fourth motion candidate in the other motion candidate list precedes the fifth motion candidate, and the adjustment process is applied to samples of the fourth motion candidate and is not applied to samples of the fifth motion candidate.

[0144] Clause 24. The method of clause 23, wherein the samples of the fourth motion candidate are adjusted in the same manner as the samples of the another video block.

[0145] Clause 25. The method of clause 23, wherein the samples of the fourth motion candidate are adjusted differently than the samples of the another video block.

[0146] Clause 26. A method according to Clause 21, wherein if the adjustment process is not applied to samples of the other video block, the fifth motion candidate in the other motion candidate list precedes the fourth motion candidate, the adjustment process is applied to samples of the fourth motion candidate and is not applied to samples of the fifth motion candidate.

[0147] Clause 27. The method of any of clauses 12 to 20, wherein independently of the information, adaptive reordering of merge candidates (ARMC) is applied to the another video block.

[0148] Clause 28. A method for video processing, comprising: determining cost information associated with an adjustment process based on codec information for a conversion between a current video block of the video and a bitstream of the video, in which samples of the video block are adjusted; determining target information about the adjustment process for the current video block based on the cost information; and performing the conversion based on the target information.

[0149] Clause 29. The method of clause 28, wherein the target information comprises how to adjust a plurality of samples of the current video block.

[0150] Clause 30. The method of Clause 28, wherein the target information comprises whether to flip a plurality of samples of the current video block horizontally or vertically.

[0151] Clause 31. A method according to any one of clauses 29 to 30, wherein the cost information includes costs of multiple schemes for the adjustment process, and the target information indicates that the multiple samples of the current video block are adjusted based on a scheme with a minimum cost among the multiple schemes.

[0152] Clause 32. The method of clause 28, wherein the target information comprises whether the adjustment process is applied to a plurality of samples of the current video block.

[0153] Clause 33. The method of clause 32, wherein the cost information comprises a first cost determined when the adjustment process is applied to the plurality of samples and a second cost determined when the adjustment process is not applied to the plurality of samples.

[0154] Clause 34. A method according to clause 33, wherein if the first cost is less than the second cost, the target information indicates that the adjustment process is applied to the multiple samples; and if the first cost is greater than the second cost, the target information indicates that the adjustment process is not applied to the multiple samples.

[0155] Clause 35. The method of clause 28, wherein the target information comprises whether the adjustment process is applied to a plurality of samples of the current video block and how to adjust the plurality of samples.

[0156] Clause 36. A method according to Clause 35, wherein the cost information includes a first cost, a second cost and a third cost, the first cost being determined by the adjustment process not being applied to the multiple samples, the second cost being determined by the multiple samples being adjusted based on a first scheme for the adjustment process, and the third cost being determined by the multiple samples being adjusted based on a second scheme for the adjustment process.

[0157] Clause 37. A method according to Clause 36, wherein if the first cost is less than the second cost and the third cost, the target information indicates that the adjustment process is not applied to the multiple samples, and if the second cost is less than the first cost and the third cost, the target information indicates that the multiple samples of the current video block are adjusted based on the first scheme; if the third cost is less than the first cost and the second cost, the target information indicates that the multiple samples of the current video block are adjusted based on the second scheme.

[0158] Clause 38. The method of any one of clauses 28 to 37, wherein the cost information is determined based on the codec information and a template matching process.

[0159] Clause 39. The method of clause 38, wherein the template matching process is performed by comparing samples in a first template and a second template associated with the current video block.

[0160] Clause 40. The method of clause 39, wherein the first template comprises samples that are neighbors to the current video block, and the second template comprises samples that are neighbors to a reference video block of the current video block.

[0161] Clause 41. The method of any one of clauses 39 to 40, wherein the cost information is determined based on a cumulative sum of differences between samples in the first template and corresponding samples in the second template.

[0162] Clause 42. The method of any of clauses 39 to 40, wherein the cost information is determined based on a cumulative sum of differences between values ​​of luma samples in the first template and values ​​of corresponding luma samples in the second template.

[0163] Clause 43. A method according to any one of clauses 39 to 42, wherein the sample is a reconstructed sample, a variant based on the reconstructed sample, a predicted sample, or a variant based on the predicted sample.

[0164] Clause 44. A method according to any one of clauses 28 to 43, wherein the target information is indicated in the bitstream.

[0165] Clause 45. The method of any one of clauses 28 to 43, wherein a syntax element indicative of the target information is included in the bitstream.

[0166] Clause 46. The method of clause 45, wherein the syntax element comprises one of: a flag, an index, a parameter, or a variable.

[0167] Clause 47. A method according to any one of clauses 1 to 27 and 29 to 48, wherein the plurality of samples comprises one of: reconstructed samples of the current video block, original samples of the current video block, or predicted samples of the current video block.

[0168] Clause 48. A method according to any one of clauses 1 to 27 and 29 to 48, wherein the adjustment process includes at least one of the following: reordering the multiple samples, flipping the multiple samples, shifting the multiple samples, rotating the multiple samples, or transforming the multiple samples.

[0169] Clause 49. The method of clause 48, wherein the plurality of samples are transformed according to one of: an M-parameter model, where M is an integer, an affine model, a linear model, or a projective model.

[0170] Clause 50. The method of Clause 48, wherein the plurality of samples are flipped in a horizontal direction or a vertical direction.

[0171] Clause 51. A method according to any one of clauses 1 to 50, wherein the adjustment process is applied based on at least one of: information of a video block of the video, information of a codec unit CU of the video, information of a prediction unit PU of the video, or information of a transform unit TU of the video.

[0172] Clause 52. A method according to any one of clauses 1 to 50, wherein the adjustment process is applied independently of at least one of: information of tiles of the video, information of strips of the video, or information of pictures of the video.

[0173] Clause 53. A method according to any one of clauses 1 to 52, wherein whether to apply the method and / or how to apply the method is indicated at one of the following: sequence level, picture group level, picture level, slice level, or tile group level.

[0174] Clause 54. A method according to any one of clauses 1 to 52, wherein whether to apply the method and / or how to apply the method is indicated in one of the following: a sequence header, a picture header, a sequence parameter set (SPS), a video parameter set (VPS), a dependency parameter set (DPS), decoding capability information (DCI), a picture parameter set (PPS), an adaptation parameter set (APS), a slice header, or a tile group header.

[0175] Clause 55. A method according to any one of clauses 1 to 52, wherein whether to apply the method and / or how to apply the method is indicated at an area containing more than one sample or pixel.

[0176] Clause 56. A method according to clause 55, wherein the region includes at least one of the following: a prediction block (PB), a transform block (TB), a codec block (CB), a prediction unit (PU), a transform unit (TU), a codec unit (CU), a virtual pipeline data unit (VPDU), a codec tree unit (CTU), a CTU row, a slice, a tile, or a sub-picture.

[0177] Clause 57. A method according to any one of clauses 1 to 56, wherein whether to apply the method and / or how to apply the method depends on the codec information.

[0178] Clause 58. The method according to clause 57, wherein the codec information includes at least one of the following: block size, color format, single-tree partitioning, double-tree partitioning, color component, slice type, or picture type.

[0179] Clause 59. The method of any one of clauses 1 to 58, wherein the converting comprises encoding the current video block into the bitstream.

[0180] Clause 60. The method of any one of clauses 1 to 58, wherein the converting comprises decoding the current video block from the bitstream.

[0181] Clause 61. An apparatus for video processing, comprising: a processor and a non-transitory memory having instructions thereon, wherein the instructions, when executed by the processor, cause the processor to perform the method of any one of clauses 1 to 60.

[0182] Clause 62. A non-transitory computer-readable storage medium storing instructions that cause a processor to perform the method of any one of clauses 1 to 60.

[0183] Clause 63. A non-transitory computer-readable recording medium storing a bitstream of a video, the bitstream being generated by a method performed by a device for video processing, wherein the method comprises: generating a motion candidate list for a current video block of the video, an adjustment process being applied to multiple samples of the current video block; and generating the bitstream based on the motion candidate list.

[0184] Clause 64. A method for storing a bitstream of a video, comprising: generating a motion candidate list for a current video block of the video, an adjustment process being applied to multiple samples of the current video block; generating the bitstream based on the motion candidate list; and storing the bitstream in a non-transitory computer-readable recording medium.

[0185] Item 65. A non-transitory computer-readable recording medium storing a bitstream of a video, the bitstream being generated by a method performed by a device for video processing, wherein the method comprises: determining, based on codec information of the video, cost information associated with an adjustment process in which samples of a video block are adjusted; determining, based on the cost information, target information about the adjustment process for a current video block of the video; and generating the bitstream based on the target information.

[0186] Clause 66. A method for storing a bitstream of a video, comprising: determining, based on codec information of the video, cost information associated with an adjustment process in which samples of a video block are adjusted; determining, based on the cost information, target information about the adjustment process for a current video block of the video; generating the bitstream based on the target information; and storing the bitstream in a non-transitory computer-readable recording medium. Example Device

[0187] Fig.12 A block diagram of a computing device 1200 in which various embodiments of the present disclosure may be implemented is shown. The computing device 1200 may be implemented as a source device 110 (or video encoder 114 or 200) or a destination device 120 (or video decoder 124 or 300), or may be included in a source device 110 (or video encoder 114 or 200) or a destination device 120 (or video decoder 124 or 300).

[0188] It should be understood that Fig.12 The computing device 1200 shown in the figure is for illustration purposes only and is not intended to in any way imply any limitation on the functionality and scope of the embodiments of the present disclosure.

[0189] like Fig.12 As shown, computing device 1200 includes a general computing device 1200. Computing device 1200 may include at least one or more processors or processing units 1210, memory 1220, storage unit 1230, one or more communication units 1240, one or more input devices 1250, and one or more output devices 1260.

[0190] In some embodiments, the computing device 1200 can be implemented as any user terminal or server terminal with computing capabilities. The server terminal can be a server provided by a service provider, a large computing device, etc. The user terminal can be, for example, any type of mobile terminal, fixed terminal or portable terminal, including a mobile phone, a station, a unit, a device, a multimedia computer, a multimedia tablet computer, an Internet node, a communicator, a desktop computer, a laptop computer, a notebook computer, a netbook computer, a personal communication system (PCS) device, a personal navigation device, a personal digital assistant (PDA), an audio / video player, a digital camera / camcorder, a positioning device, a television receiver, a radio broadcast receiver, an electronic book device, a gaming device, or any combination thereof, and includes accessories and peripherals of these devices, or any combination thereof. It is conceivable that the computing device 1200 can support any type of interface to the user (such as a "wearable" circuit device, etc.).

[0191] The processing unit 1210 may be a physical processor or a virtual processor and may implement various processes based on a program stored in the memory 1220. In a multi-processor system, multiple processing units execute computer executable instructions in parallel to improve the parallel processing capability of the computing device 1200. The processing unit 1210 may also be referred to as a central processing unit (CPU), a microprocessor, a controller, or a microcontroller.

[0192] The computing device 1200 typically includes various computer storage media. Such media can be any media accessible by the computing device 1200, including but not limited to volatile media and non-volatile media, or removable media and non-removable media. The memory 1220 can be a volatile memory (e.g., a register, a cache, a random access memory (RAM)), a non-volatile memory (such as a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM) or flash memory), or any combination thereof. The storage unit 1230 can be any removable or non-removable medium, and can include machine-readable media, such as a memory, a flash drive, a disk, or other media that can be used to store information and / or data and can be accessed in the computing device 1200.

[0193] The computing device 1200 may also include additional removable / non-removable storage media, volatile / non-volatile storage media. Fig.12 Although not shown in the figure, a magnetic disk drive for reading from and / or writing to a removable nonvolatile magnetic disk and an optical disk drive for reading from and / or writing to a removable nonvolatile optical disk may be provided. In this case, each drive may be connected to the bus (not shown) via one or more data medium interfaces.

[0194] The communication unit 1240 communicates with another computing device via a communication medium. In addition, the functionality of the components in the computing device 1200 can be implemented by a single computing cluster or multiple computing machines that can communicate via a communication connection. Therefore, the computing device 1200 can operate in a networked environment using logical connections to one or more other servers, networked personal computers (PCs), or other general network nodes.

[0195] The input device 1250 may be one or more of various input devices, such as a mouse, keyboard, trackball, voice input device, etc. The output device 1260 may be one or more of various output devices, such as a display, a speaker, a printer, etc. With the aid of the communication unit 1240, the computing device 1200 may also communicate with one or more external devices (not shown), such as storage devices and display devices, and the computing device 1200 may also communicate with one or more devices that enable a user to interact with the computing device 1200, or any device that enables the computing device 1200 to communicate with one or more other computing devices (e.g., a network card, a modem, etc.), if necessary. Such communication may be performed via an input / output (I / O) interface (not shown).

[0196] In some embodiments, some or all components of the computing device 1200 may also be arranged in a cloud computing architecture rather than being integrated in a single device. In a cloud computing architecture, components may be provided remotely and work together to implement the functions described in the present disclosure. In some embodiments, cloud computing provides computing, software, data access and storage services, which will not require the end user to know the physical location or configuration of the system or hardware that provides these services. In various embodiments, cloud computing provides services via a wide area network (e.g., the Internet) using a suitable protocol. For example, a cloud computing provider provides applications via a wide area network, which can be accessed through a web browser or any other computing component. The software or components of the cloud computing architecture and the corresponding data may be stored on a remote server. The computing resources in a cloud computing environment may be merged or distributed at the location of a remote data center. Cloud computing infrastructures may provide services through a shared data center, although they appear as a single access point for users. Therefore, cloud computing architectures may be used to provide components and functions described herein from a service provider at a remote location. Alternatively, they may be provided by a conventional server, or installed directly or otherwise on a client device.

[0197] In an embodiment of the present disclosure, the computing device 1200 may be used to implement video encoding / decoding. The memory 1220 may include one or more video encoding / decoding modules 1225 having one or more program instructions. These modules can be accessed and executed by the processing unit 1210 to perform the functions of the various embodiments described herein.

[0198] In an example embodiment performing video encoding, input device 1250 may receive video data as input 1270 to be encoded. The video data may be processed by, for example, video codec module 1225 to generate an encoded bitstream. The encoded bitstream may be provided as output 1280 via output device 1260.

[0199] In an example embodiment performing video decoding, input device 1250 may receive an encoded bitstream as input 1270. The encoded bitstream may be processed by, for example, video codec module 1225 to generate decoded video data. The decoded video data may be provided as output 1280 via output device 1260.

[0200] Although the present disclosure has been specifically shown and described with reference to the preferred embodiments of the present disclosure, it will be understood by those skilled in the art that various changes can be made in form and detail without departing from the spirit and scope of the present application as defined by the appended claims. These changes are intended to be encompassed by the scope of the present application. Therefore, the foregoing description of the embodiments of the present application is not intended to be limiting.

Claims

1. A method for video processing, comprising: For conversion between a current video block of a video and a bitstream of the video, a motion candidate list for the current video block is generated, and an adjustment process is applied to a plurality of samples of the current video block; as well as The converting is performed based on the motion candidate list.

2. The method of claim 1, wherein the motion candidate list is different from an intra block copy (IBC) merge motion candidate list and an IBC advanced motion vector prediction (AMVP) motion candidate list for the current video block.

3. The method according to any one of claims 1 to 2, wherein the motion candidates in the motion candidate list are selected from a plurality of motion candidates, and samples of each of the plurality of motion candidates are adjusted in the same manner as the plurality of samples of the current video block. 4 . The method according to claim 1 , wherein the motion candidate in the motion candidate list is selected from a plurality of motion candidates, and the adjustment process is applied to samples of each motion candidate in the plurality of motion candidates. 5 . The method according to claim 1 , wherein the motion candidate list is generated independently of the adjustment process. 6 . The method of claim 1 , wherein the motion candidate list comprises a first motion candidate that is not adjacent to the current video block. The method of claim 6 , wherein the adjustment process is applied to the first motion candidate.

8. The method of any one of claims 6 to 7, wherein samples of the first motion candidate are adjusted in the same manner as the plurality of samples of the current video block. 9 . The method of claim 6 , wherein the first motion candidate is added to the motion candidate list independently of whether the adjustment process is applied to samples of the first motion candidate. 10 . The method according to claim 1 , wherein the motion candidate list includes motion candidates generated according to a rule based on an averaging process, a cropping process, or a scaling process.

11. The method of claim 1, wherein the motion candidate list is an IBC merge motion candidate list or an IBC AMVP motion candidate list for the current video block.

12. The method according to any one of claims 1 to 11, wherein based on information about how to adjust samples of a video block in the adjustment process, another motion candidate list is generated for another video block of the video, and the other video block is different from the current video block. 13 . The method of claim 12 , wherein the another motion candidate list includes the information associated with the motion candidates in the another motion candidate list. The method of claim 13 , wherein the adjustment process is applied to samples of the another video block.

15. The method of claim 12, wherein if the adjustment process is applied to samples of the other video block, samples of each motion candidate in the other motion candidate list are adjusted in the same manner as the samples of the other video block.

16. The method of claim 12, wherein if the adjustment process is applied to samples of the another video block, the adjustment process is applied to samples of each motion candidate in the another motion candidate list.

17. The method of claim 16, wherein samples of each motion candidate in the another motion candidate list are adjusted in the same manner as the samples of the another video block.

18. The method of claim 16, wherein samples of motion candidates in the another motion candidate list are adjusted differently than the samples of the another video block.

19. The method of claim 12, wherein if the adjustment process is not applied to samples of the another video block, then the adjustment process is not applied to samples of each motion candidate in the another motion candidate list.

20. The method according to any one of claims 1 to 11, wherein another motion candidate list is generated for another video block of the video independently of the information about how to adjust the samples of the video block in the adjustment process, and the other video block is different from the current video block.

21. The method of any one of claims 12 to 20, wherein adaptive reordering of merging candidates (ARMC) of the further video block depends on the information.

22. The method of claim 21 , wherein if the adjustment process is applied to samples of the other video block, a second motion candidate precedes a third motion candidate in the other motion candidate list, samples of the second motion candidate are adjusted in the same manner as the samples of the other video block, and samples of the third motion candidate are adjusted in a different manner than the samples of the other video block.

23. The method of claim 21, wherein if the adjustment process is applied to samples of the other video block, a fourth motion candidate precedes a fifth motion candidate in the other motion candidate list, and the adjustment process is applied to samples of the fourth motion candidate and is not applied to samples of the fifth motion candidate.

24. The method of claim 23, wherein the samples of the fourth motion candidate are adjusted in the same manner as the samples of the another video block.

25. The method of claim 23, wherein the samples of the fourth motion candidate are adjusted differently than the samples of the another video block.

26. The method of claim 21, wherein if the adjustment process is not applied to samples of the another video block, a fifth motion candidate precedes a fourth motion candidate in the another motion candidate list, the adjustment process is applied to samples of the fourth motion candidate and is not applied to samples of the fifth motion candidate.

27. The method of any one of claims 12 to 20, wherein independently of the information, adaptive reordering of merge candidates (ARMC) is applied to the another video block.

28. A method for video processing, comprising: determining, based on codec information of a video for a conversion between a current video block of the video and a bitstream of the video, cost information associated with an adjustment process in which samples of the video block are adjusted; determining target information about the adjustment process for the current video block based on the cost information; as well as The converting is performed based on the target information.

29. The method of claim 28, wherein the target information comprises how to adjust a plurality of samples of the current video block.

30. The method of claim 28, wherein the target information comprises whether to flip a plurality of samples of the current video block horizontally or vertically.

31. The method according to any one of claims 29 to 30, wherein the cost information comprises costs of a plurality of schemes for the adjustment process, and the target information indicates that the plurality of samples of the current video block are adjusted based on a scheme having a minimum cost among the plurality of schemes.

32. The method of claim 28, wherein the target information comprises whether the adjustment process is applied to a plurality of samples of the current video block.

33. The method of claim 32, wherein the cost information comprises a first cost and a second cost, the first cost being determined when the adjustment process is applied to the plurality of samples, the second cost being determined when the adjustment process is not applied to the plurality of samples.

34. The method of claim 33, wherein if the first cost is less than the second cost, the target information indicates that the adjustment process is applied to the plurality of samples; and If the first cost is greater than the second cost, the target information indicates that the adjustment process is not applied to the plurality of samples.

35. The method of claim 28, wherein the target information comprises whether the adjustment process is applied to a plurality of samples of the current video block and how to adjust the plurality of samples.

36. A method according to claim 35, wherein the cost information includes a first cost, a second cost and a third cost, the first cost is determined by the adjustment process not being applied to the multiple samples, the second cost is determined by the multiple samples being adjusted based on the first scheme for the adjustment process, and the third cost is determined by the multiple samples being adjusted based on the second scheme for the adjustment process.

37. The method of claim 36, wherein if the first cost is less than the second cost and the third cost, then the target information indicates that the adjustment process is not applied to the plurality of samples, If the second cost is less than the first cost and the third cost, the target information indicates that the plurality of samples of the current video block are adjusted based on the first scheme; If the third cost is less than the first cost and the second cost, the target information indicates that the plurality of samples of the current video block are adjusted based on the second scheme.

38. The method according to any one of claims 28 to 37, wherein the cost information is determined based on the codec information and a template matching process.

39. The method of claim 38, wherein the template matching process is performed by comparing samples in a first template and a second template associated with the current video block.

40. The method of claim 39, wherein the first template comprises samples that are neighbors to the current video block, and the second template comprises samples that are neighbors to a reference video block of the current video block.

41. The method of any one of claims 39 to 40, wherein the cost information is determined based on a cumulative sum of differences between samples in the first template and corresponding samples in the second template.

42. The method of any one of claims 39 to 40, wherein the cost information is determined based on a cumulative sum of differences between values ​​of luma samples in the first template and values ​​of corresponding luma samples in the second template.

43. The method of any one of claims 39 to 42, wherein the sample is a reconstructed sample, a variant based on the reconstructed sample, a predicted sample, or a variant based on the predicted sample.

44. A method according to any one of claims 28 to 43, wherein the target information is indicated in the bitstream.

45. The method according to any one of claims 28 to 43, wherein a syntax element indicating the target information is included in the bitstream.

46. ​​The method of claim 45, wherein the syntax element comprises one of: Logo, index, parameters, or variable.

47. The method of any one of claims 1 to 27 and 29 to 48, wherein the plurality of samples comprises one of: reconstructed samples of the current video block, the original samples of the current video block, or The predicted samples of the current video block.

48. The method of any one of claims 1 to 27 and 29 to 48, wherein the adjustment process comprises at least one of the following: reordering the plurality of samples, flipping the plurality of samples, shifting the plurality of samples, rotating the plurality of samples, or The plurality of samples are transformed.

49. The method of claim 48, wherein the plurality of samples are transformed according to one of: M parameter model, M is an integer, Affine model, Linear models, or Projection model.

50. The method of claim 48, wherein the plurality of samples are flipped in a horizontal direction or a vertical direction.

51. The method of any one of claims 1 to 50, wherein the adjustment process is applied based on at least one of: Information about the video chunk of the video, Information of the codec unit CU of the video, Information of the prediction unit PU of the video, or Information of the transform unit TU of the video.

52. The method of any one of claims 1 to 50, wherein the adjustment process is applied independently of at least one of: Information about the tiles of the video, information about the strip of video, or Information about the pictures of the video.

53. A method according to any one of claims 1 to 52, wherein whether to apply the method and / or how to apply the method is indicated at one of: Sequence level, Picture group level, Picture level, Stripe level, or Tile group level.

54. The method according to any one of claims 1 to 52, wherein whether to apply the method and / or how to apply the method is indicated in one of the following: Sequence header, Picture header, Sequence Parameter Set (SPS), Video Parameter Set (VPS), Dependency Parameter Set (DPS), Decoding Capability Information (DCI), Picture Parameter Set (PPS), Adaptive Parameter Set (APS), Strip header, or Tile group header.

55. A method according to any one of claims 1 to 52, wherein whether and / or how to apply the method is indicated at an area containing more than one sample or pixel.

56. The method of claim 55, wherein the region comprises at least one of: Prediction Block (PB), Transform Block (TB), Codec Block (CB), Prediction Unit (PU), Transformation Unit (TU), Codec Unit (CU), Virtual Pipeline Data Unit (VPDU), Codec Tree Unit (CTU), CTU line, Strips, tiles, or Sub-picture.

57. The method according to any one of claims 1 to 56, wherein whether to apply the method and / or how to apply the method depends on the codec information.

58. The method according to claim 57, wherein the codec information comprises at least one of the following: Block size, Color format, Single and double tree partitioning, Double tree partitioning, Color components, Strip type, or Image type.

59. The method of any one of claims 1 to 58, wherein the converting comprises encoding the current video block into the bitstream.

60. The method of any one of claims 1 to 58, wherein the converting comprises decoding the current video block from the bitstream.

61. An apparatus for video processing, comprising: A processor and a non-transitory memory having instructions thereon, wherein the instructions, when executed by the processor, cause the processor to perform the method according to any one of claims 1 to 60.

62. A non-transitory computer readable storage medium storing instructions, the instructions causing a processor to execute the method according to any one of claims 1 to 60.

63. A non-transitory computer-readable recording medium storing a bit stream of a video, the bit stream being generated by a method performed by an apparatus for video processing, wherein the method comprises: generating a motion candidate list for a current video block of the video, the adjustment process being applied to a plurality of samples of the current video block; as well as The bitstream is generated based on the motion candidate list.

64. A method for storing a bitstream of a video, comprising: generating a motion candidate list for a current video block of the video, the adjustment process being applied to a plurality of samples of the current video block; generating the bitstream based on the motion candidate list; as well as The bit stream is stored in a non-transitory computer-readable recording medium.

65. A non-transitory computer-readable recording medium storing a bit stream of a video, the bit stream being generated by a method performed by an apparatus for video processing, wherein the method comprises: Based on the codec information of the video, determining cost information associated with an adjustment process in which samples of the video block are adjusted; determining, based on the cost information, target information regarding the adjustment process for a current video block of the video; as well as The bitstream is generated based on the target information.

66. A method for storing a bitstream of a video, comprising: Determining, based on codec information of the video, cost information associated with an adjustment process in which samples of a video block are adjusted; determining, based on the cost information, target information regarding the adjustment process for a current video block of the video; generating the bitstream based on the target information; as well as The bit stream is stored in a non-transitory computer-readable recording medium.

Images