Method and device for video processing and medium

Abstract

The embodiment of the invention provides a video processing scheme. A method for video processing is presented. The method includes performing a conversion between a current video block of a video and a bitstream of the video, wherein a first syntax element is included in the bitstream and indicates whether an adjustment process is applied to a plurality of samples of the current video block.

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] The disclosed embodiment provides a solution for video processing.

[0004] In a first aspect, a method for video processing is proposed. The method comprises: performing conversion between a current video block of a video and a bitstream of the video, wherein a first syntax element is included in the bitstream and indicates whether an adjustment process is applied to a plurality of samples of the current video block.

[0005] According to the method of the first aspect of the present disclosure, whether the samples of the video block are to be adjusted (e.g., reordered, flipped, etc.) is signaled in the bitstream. 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 comprising: determining, for conversion between a current video block of a video and a bitstream of the video, information about an adjustment process for adjusting samples of the video block based on at least one video block of the video, the at least one video block being encoded and decoded before the current video block.

[0007] According to the method of the second aspect of the present disclosure, information about the adjustment process is determined for the current video block based on one or more coded video blocks. Compared with the traditional scheme, the proposed method can advantageously better support sample adjustment, thereby achieving higher coding gain and improving coding efficiency.

[0008] In a third aspect, a device for video processing is provided. The device comprises 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 or 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 or 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: performing conversion between a current video block of the video and a bitstream, wherein a first syntax element is included in the bitstream and indicates whether an adjustment process is applied to a plurality of samples of the current video block.

[0011] In a sixth aspect, a method for storing a bitstream of a video is provided. The method includes: performing conversion between a current video block of the video and a bitstream; and storing the bitstream in a non-transitory computer-readable recording medium, wherein a first syntax element is included in the bitstream and indicates whether an adjustment process is applied to a plurality of samples of the current video block.

[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: based on at least one video block of the video, for a current video block of the video, determining information about an adjustment process for adjusting samples of the video block, at least one video block being encoded and decoded before the current video block; and generating the bitstream based on the information.

[0013] In an eighth aspect, a method for storing a bitstream of a video is provided. The method includes: determining information about an adjustment process of adjusting samples of a video block for a current video block of the video based on at least one video block of the video, the at least one video block being encoded and decoded before the current video block; generating a bitstream based on the 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 1 A 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 codec 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 "including", "comprising", 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 may 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 coded representation of the video data. The bitstream may include coded pictures and associated data. The coded pictures are coded representations of pictures. The associated data may include sequence parameter sets, picture parameter sets, and other grammatical structures. The I / O interface 116 may include a modulator / demodulator and / or a transmitter. The coded video data may be directly transmitted to the destination device 120 via the network 130A via the I / O interface 116. The coded 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 and decoding 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 codec 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 can also 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 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 virtual buffer concept is used to describe the allowable reference area for IBC prediction mode and valid block vectors. 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; for a CTU of size 64×64, the size of ibcBuf is 256×64; and 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), W v =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 an invalid value of -1. - When starting to decode a VPDU (xVPDU, yVPDU) relative to the top left corner of the picture, set ibcBuf[x][y]=-1, where x=xVPDU%wIbcBuf,...,xVPDU%wIbcBuf+W v -1; y=yVPDU%ctbSize,…,yVPDU%ctbSize+W v -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 and decoding. 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 scanning order is applied to scan sub-blocks within a transformed block and also to scan positions within the sub-blocks; - no signaling of the last (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 and above sig_coeff_flag values; - 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 of 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, then 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, then 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, respectively. - 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 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 encoding and decoding pass, 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: pred=max(X0,X1); if(absCoeff == pred) absCoeffMod = 1; else absCoeffMod = (absCoeff <pred)?absCoeff+1:absCoeff; 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 the 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 the run type COPY_ABOVE, or whether the previously scanned sample and the current sample both have the 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 codec pass, index values ​​(for INDEX mode) and quantized escape colors are grouped and encoded using CABAC bypass codec in another codec pass. This separation of context codec binary bits and bypass codec 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 with a single tree, the palette is applied on the Y, Cb, Cr components jointly, 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 HEVC SCC. 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 updating is slightly modified as follows. Since the local dual-tree block contains only luminance (or chroma) components, so the predictor update process uses the signaled values ​​of the luma (or chroma) components and fills in the "missing" chroma (or luma) components by setting them to default values ​​(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 the 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 enabled only 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 enabling / disabling RD checking for 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. - Reuse the same ACT enable / disable decision when a CU is obtained through different split paths. 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 split path, instead of checking the RD cost of the two spaces, the stored color space decision will be directly reused. -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 the two 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 (Search Range_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 region, 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). 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 move. 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 encoding solution 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 / SAO / ALF may be used based on whether and / or how samples are reordered. 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 About 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. 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. 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 using one or more of the modes / techniques listed below, Then the reordering process can 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 size W×H of the video unit meets one or more of the rules listed below, Then the reordering process can 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 approach is 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 based on luma mapping of 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. 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 block can be reordered / transformed / flipped / rotated to obtain higher codec gain. The following issues can be considered: 1. Signaling of sample reordering. 2. Storage of sample reordering status. 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 the signaling of sample reordering (eg, the first problem and related problems), the following approach 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 (e.g., such as 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, 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 may be 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. 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, 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 may be 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. 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. 4.2 Regarding the storage of sample reordering states (eg, the second question and related questions), 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 4.3 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 / PPS / slice header / tile group header. 4.4 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. 4.5 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.

[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 FIG. 1 is a flow chart of a method 1000 for video processing according to some embodiments of the present disclosure. Fig.10 As shown, at 1002, a conversion is performed between a current video block of a video and a bitstream of the video. In one example, the conversion may include encoding the current video block into the bitstream. Alternatively or additionally, the conversion may include decoding the current video block from the bitstream.

[0075] In some embodiments, the first syntax element is included in the bitstream and indicates whether the adjustment process is applied to multiple samples of the current video block. In one example, the first syntax element can be a flag. In another example, the first syntax element can be an index. In another example, the first syntax element can be a variable. In yet another example, the first syntax element can 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 regard.

[0076] 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, moving the plurality of samples, rotating the plurality of samples, transforming the plurality of samples, etc. As used herein, information about how to adjust the samples of the video block in the adjustment process may also be referred to as an adjustment method, a scheme for the adjustment process, or a type of adjustment process. 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 regard.

[0077] In view of the above, a signal is used in the bitstream to inform whether the samples of the video block will be adjusted (e.g., reordered, flipped, etc.). Compared with the traditional scheme, the proposed method can advantageously better support sample adjustment, thereby achieving higher codec gain and improving codec efficiency.

[0078] In some embodiments, a prediction scheme may be used to encode and decode the current video block. As an example and not limitation, the prediction scheme may include intra-frame template matching, intra-frame block copy (IBC) advanced motion vector prediction (AMVP), IBC merging, etc.

[0079] In some embodiments, the first indication may be included in the bitstream and indicates that the current video block is encoded and decoded using intra template matching. For example, the first indication may be an intra template matching usage flag. In one example, if the intra template matching usage flag indicates that the current video block is encoded and decoded using intra template matching, then a syntax element indicating that the adjustment process is applied to the video block encoded and decoded using intra template matching may be signaled.

[0080] In some alternative embodiments, the second indication may be included in the bitstream and indicates that the current video block is coded with IBC AMVP. For example, the second indication may be an IBC AMVP flag. In one example, if the IBC AMVP flag indicates that the current video block is coded with IBC AMVP, then a syntax element indicating that the adjustment process is applied to the video block coded with IBC AMVP may be signaled.

[0081] In some further embodiments, a third indication may be included in the bitstream and indicates that the current video block is coded using IBC merge. For example, the third indication may be an IBC merge flag. In one example, if the IBC merge flag indicates that the current video block is coded using IBC merge, then a syntax element indicating that the adjustment process is applied to the video block coded using IBC merge may be signaled.

[0082] In some embodiments, a second syntax element indicating how to adjust the plurality of samples may be included in the bitstream. Additionally or alternatively, a single syntax element indicating the type of adjustment process (eg, no flip, horizontal flip, or vertical flip) may be included in the bitstream.

[0083] In some embodiments, if the first indication indicates that the current video block is encoded and decoded using intra-frame template matching, a single syntax element indicating the type of the adjustment process may be included in the bitstream. For example, the first indication is an intra-frame template matching usage flag. In some alternative embodiments, if the second indication indicates that the current video block is encoded and decoded using IBC AMVP, a single syntax element indicating the type of the adjustment process may be included in the bitstream. For example, the second indication may be an IBC AMVP flag. In some further embodiments, if the third indication indicates that the current video block is encoded and decoded using IBC merging, a single syntax element indicating the type of the adjustment process may be included in the bitstream. For example, the third indication may be an IBC merge flag.

[0084] In some embodiments, the first syntax element may further indicate how to adjust the multiple samples. For example, the first value of the first syntax element may indicate that the adjustment process is not applied to the multiple samples. The second value of the first syntax element may indicate that the first type of adjustment process is applied to the multiple samples. In addition, the third value of the first syntax element may indicate that the second type of adjustment process is applied to the multiple samples. By way of example and not limitation, the first value is 0, the second value is 1, and the third value is 2.

[0085] In some embodiments, context encoding and decoding may be performed on at least one syntax element associated with the adjustment process. In one example, the at least one syntax element may include a first syntax element. In some embodiments, the context used to encode and decode the at least one syntax element depends on encoding and decoding information of at least one neighboring block or at least one neighboring sample of the current video block.

[0086] In some embodiments, information about the adjustment process may be stored. The information may include whether the adjustment process is applied to multiple samples of the current video block and / or how the multiple samples are adjusted. In one example, the stored information may be used to encode and decode another video block of a video different from the current video block. For example, if the stored information indicates that multiple samples of the current video block are rotated, then the samples of the other video block may also be rotated.

[0087] In some embodiments, the information may be stored in at least one buffer. By way of example and not limitation, the at least one buffer may include one or more line buffers, tables, picture buffers, compressed picture buffers, temporal buffers, etc. In some alternative embodiments, the information may be stored in a historical motion vector table, such as an HMVP table.

[0088] In some additional or alternative embodiments, codec information of the current video block may be stored for use in determining the context of syntax elements associated with the adaptation process.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] According to another embodiment of the present disclosure, a non-transitory computer-readable storage medium is provided. The non-transitory computer-readable storage medium stores a bitstream of a video generated by a method performed by a device for video processing. In the method, conversion is performed between a current video block of the video and a bitstream. A first syntax element is included in the bitstream and indicates whether an adjustment process is applied to a plurality of samples of the current video block.

[0093] According to some further embodiments of the present disclosure, a method for storing a bitstream of a video is provided. In the method, a conversion is performed between a current video block of the video and a bitstream. A first syntax element is included in the bitstream and indicates whether an adjustment process is applied to a plurality of samples of the current video block. In addition, the bitstream is stored in a non-transitory computer-readable recording medium.

[0094] 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 starts at 1102, where information about an adjustment process for adjusting samples of a video block is determined for a current video block based on at least one video block of a video. At least one video block is encoded and decoded before the current video block. The samples of the video block 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 samples of the video block, flipping samples of the video block, moving samples of the video block, rotating samples of the video block, transforming samples of the video block, etc. 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.

[0095] In some embodiments, the information may include whether the adjustment process should be applied to multiple samples of the current video block. In some alternative embodiments, the information may include how to adjust the multiple samples. In other embodiments, the information may include whether the adjustment process is applied to multiple samples of the current video block, and how to adjust the multiple samples.

[0096] In some embodiments, if the adjustment process is applied to samples of at least one video block, the adjustment process may be applied to multiple samples of the current video block. In other words, information about whether the adjustment process is applied to multiple samples of the current video block may be inherited from at least one video block.

[0097] In some additional or alternative embodiments, if the adjustment process is applied to samples of at least one video block, the adjustment process is applied to multiple samples of the current video block, and the multiple samples of the current video block are adjusted in the same manner as the samples of the at least one video block. In other words, information about how to adjust multiple samples of the current video block can be inherited from the at least one video block.

[0098] At 1104, a conversion is performed based on the information. In one example, the conversion may include encoding the current video block into a video stream. Alternatively or additionally, the conversion may include decoding the current video block from a bitstream.

[0099] In view of the above, information about the adjustment process of the current video block is determined based on one or more coded video blocks. Compared with the traditional scheme, the proposed method can advantageously better support sample adjustment, thereby achieving higher coding gain and improving coding efficiency.

[0100] In some embodiments, the at least one video block may include a neighboring video block adjacent to the current video block and / or a neighboring video block not adjacent to the current video block. In some alternative embodiments, the at least one video block may be included in a history-based motion table (such as a history-based motion vector prediction (HMVP) table) for the current video block.

[0101] In some embodiments, at least one video block may be a temporal motion candidate for the current video block. Alternatively, at least one video block may be included in an IBC merge candidate list or an IBC AMVP candidate list for the current video block. In some further embodiments, at least one video block may be included in a motion candidate list generated for the current video block.

[0102] In some embodiments, intra template matching, IBC AMVP, IBC merging, etc. may be used to encode and decode the current video block.

[0103] In some embodiments, the at least one video block may be adjacent to the current video block.The information about the adjustment process may be determined based on a predefined rule associated with encoded information of neighboring samples of the at least one video block or the current video block.

[0104] In some embodiments, the first indication may be included in the bitstream and indicates that the current video block is encoded and decoded using intra template matching. As an example and not limitation, the first indication may be an intra template matching flag.

[0105] In some embodiments, if the first indication indicates that the current video block is encoded and decoded using intra template matching, the information includes how to adjust the multiple samples, and a syntax element indicating whether the adjustment process is applied to the multiple samples can be included in the bitstream. In other words, how to adjust the multiple samples can be determined based on a pre-refined rule, and whether the adjustment process is applied to the multiple samples can be signaled in the bitstream.

[0106] In some alternative embodiments, if the first indication indicates that the current video block is encoded using intra template matching, the information may include whether the adjustment process is applied to the plurality of samples, and a syntax element indicating how to adjust the plurality of samples may be included in the bitstream. In other words, how to adjust the plurality of samples may be signaled in the bitstream, and whether the adjustment process is applied to the plurality of samples may be determined based on a pre-refined rule.

[0107] In some embodiments, the second indication may be included in the bitstream and indicates that the current video block is coded with IBC AMVP. As an example and not limitation, the second indication may be an IBC AMVP flag.

[0108] In some embodiments, if the second indication indicates that the current video block is coded and decoded using IBC AMVP, the information includes how to adjust the multiple samples, and a syntax element indicating whether the adjustment process is applied to the multiple samples is included in the bitstream. In other words, how to adjust the multiple samples can be determined based on a pre-refined rule, and whether the adjustment process is applied to the multiple samples can be signaled in the bitstream.

[0109] In some embodiments, if the second indication indicates that the current video block is coded and decoded using IBC AMVP, the information may include whether the adjustment process is applied to the plurality of samples, and a syntax element indicating how to adjust the plurality of samples is included in the bitstream. In other words, how to adjust the plurality of samples may be signaled in the bitstream, and whether the adjustment process is applied to the plurality of samples may be determined based on a pre-refined rule.

[0110] In some embodiments, the third indication may be included in the bitstream and indicates that the current video block is encoded and decoded using IBC merging. As an example and not limitation, the third indication may be an IBC merge flag.

[0111] In some embodiments, if the third indication indicates that the current video block is encoded and decoded using IBC merging, the information may include how to adjust the multiple samples, and a syntax element indicating whether the adjustment process is applied to the multiple samples may be included in the bitstream. In other words, how to adjust the multiple samples may be determined based on a pre-refined rule, and whether the adjustment process is applied to the multiple samples may be signaled in the bitstream.

[0112] In some embodiments, if the third indication indicates that the current video block is encoded and decoded using IBC merging, the information may include whether the adjustment process is applied to the plurality of samples, and a syntax element indicating how to adjust the plurality of samples is included in the bitstream. In other words, how to adjust the plurality of samples may be signaled in the bitstream, and whether the adjustment process is applied to the plurality of samples may be determined based on a pre-refined rule.

[0113] In some embodiments, information about the adjustment process may be stored. In one example, the stored information may be used to encode and decode another video block of a video different from the current video block. For example, if the stored information indicates that multiple samples of the current video block are rotated, samples of another video block may also be rotated.

[0114] In some embodiments, the information may be stored in at least one buffer. By way of example and not limitation, the at least one buffer may include one or more line buffers, tables, picture buffers, compressed picture buffers, temporal buffers, etc. In some alternative embodiments, the information may be stored in a historical motion vector table, such as an HMVP table.

[0115] In some additional or alternative embodiments, codec information of the current video block may be stored for use in determining the context of syntax elements associated with the adaptation process.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] According to another embodiment of the present disclosure, a non-transitory computer-readable storage medium is provided. The non-transitory computer-readable storage medium stores a bitstream of a video generated by a method performed by a device for video processing. In the method, based on at least one video block of the video, for a current video block of the video, information about an adjustment process for adjusting samples of the video block is determined, and at least one video block is encoded and decoded before the current video block. In addition, a bitstream is generated based on the information.

[0120] 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 at least one video block of the video, for a current video block of the video, information about an adjustment process for adjusting samples of the video block is determined, and at least one video block is encoded and decoded before the current video block. In addition, a bitstream is generated based on the information, and the bitstream is stored in a non-transitory computer-readable recording medium.

[0121] Embodiments of the present disclosure may be described according to the following clauses, features of which may be combined in any reasonable way.

[0122] Clause 1. A method for video processing, comprising: performing a conversion between a current video block of a video and a bitstream of the video, wherein a first syntax element is included in the bitstream and indicates whether an adjustment process is applied to a plurality of samples of the current video block.

[0123] Clause 2. The method according to clause 1, wherein the adjustment process comprises at least one of the following: reordering the multiple samples, flipping the multiple samples, moving the multiple samples, rotating the multiple samples, or transforming the multiple samples.

[0124] Clause 3. The method of any of clauses 1-2, wherein the current video block is encoded using a prediction scheme.

[0125] Clause 4. The method of clause 3, wherein the prediction scheme comprises one of: intra template matching, intra block copy (IBC) advanced motion vector prediction (AMVP), or IBC merge.

[0126] Clause 5. The method of any of clauses 1-4, wherein a first indication is included in the bitstream and indicates that the current video block is encoded using intra template matching.

[0127] Clause 6. The method of any of clauses 1-4, wherein a second indication is included in the bitstream and indicates that the current video block is coded with IBC AMVP.

[0128] Clause 7. The method of any of clauses 1-4, wherein a third indication is included in the bitstream and indicates that the current video block is encoded with IBC merging.

[0129] Clause 8. A method as described in any of clauses 1-7, wherein a second syntax element indicating how to adjust the plurality of samples is included in the bitstream.

[0130] Clause 9. A method according to any of clauses 1-8, wherein a single syntax element indicating the type of the adaptation process is included in the bitstream.

[0131] Clause 10. The method of any of clauses 1-8, wherein if the first indication indicates that the current video block is encoded using intra template matching, a single syntax element indicating the type of the adaptation process is included in the bitstream.

[0132] Clause 11. The method of clause 5 or 10, wherein the first indication is an intra template matching usage flag.

[0133] Clause 12. The method of any of clauses 1-8, wherein if the second indication indicates that the current video block is coded with IBC AMVP, a single syntax element indicating the type of the adaptation process is included in the bitstream.

[0134] Clause 13. The method of clause 6 or 12, wherein the second indication is an IBC AMVP flag.

[0135] Clause 14. The method of any of clauses 1-8, wherein if a third indication indicates that the current video block is encoded with IBC merging, a single syntax element indicating the type of the adjustment process is included in the bitstream.

[0136] Clause 15. The method of clause 7 or 14, wherein the third indication is an IBC merge flag.

[0137] Clause 16. A method as described in any of clauses 1-15, wherein the first syntax element further indicates how to adjust the plurality of samples.

[0138] Clause 17. A method according to any one of clauses 1-16, wherein the first value of the first syntax element indicates that the adjustment process is not applied to the multiple samples; the second value of the first syntax element indicates that a first type of adjustment process is applied to the multiple samples; and the third value of the first syntax element indicates that a second type of adjustment process is applied to the multiple samples.

[0139] Clause 18. The method of any of clauses 1-17, wherein at least one syntax element associated with the adaptation process is context-coded.

[0140] Clause 19. The method of clause 18, wherein the at least one syntax element comprises the first syntax element.

[0141] Clause 20. The method of any of clauses 18-19, wherein the context used for encoding and decoding the at least one syntax element depends on encoding and decoding information of at least one neighboring block or at least one neighboring sample of the current video block.

[0142] Clause 21. The method of any of clauses 1-20, wherein information about the adjustment process is stored.

[0143] Clause 22. The method of clause 21, wherein the information comprises at least one of: whether the adjustment process is applied to a plurality of samples of the current video block, or how the plurality of samples are adjusted.

[0144] Clause 23. A method for video processing, comprising: determining, for conversion between a current video block of a video and a bitstream of the video, information about an adjustment process for adjusting samples of the video block based on at least one video block of the video, the at least one video block being encoded and decoded before the current video block; and performing the conversion based on the information.

[0145] Clause 24. The method of clause 23, wherein the information comprises at least one of whether the adjustment process is applied to a plurality of samples of the current video block, or how the plurality of samples are adjusted.

[0146] Clause 25. A method according to any one of clauses 23-24, wherein if the adjustment process is applied to samples of the at least one video block, the adjustment process is applied to multiple samples of the current video block, or if the adjustment process is applied to samples of the at least one video block, the adjustment process is applied to multiple samples of the current video block, and the multiple samples of the current video block are adjusted in the same manner as the samples of the at least one video block.

[0147] Clause 26. The method of any of clauses 23-25, wherein the at least one video block comprises at least one of: a neighboring video block that is adjacent to the current video block; or a neighboring video block that is not adjacent to the current video block.

[0148] Clause 27. The method of any of clauses 23-25, wherein the at least one video block is included in a history-based motion table for the current video block.

[0149] Clause 28. The method of clause 27, wherein the history-based motion table is a history-based motion vector prediction (HMVP) table.

[0150] Clause 29. The method of any of clauses 23-25, wherein the at least one video block is a temporal motion candidate for the current video block.

[0151] Clause 30. The method of any of clauses 23-25, wherein the at least one video block is included in an IBC merge candidate list or an IBC AMVP candidate list for the current video block.

[0152] Clause 31. The method of any of clauses 23-25, wherein the at least one video block is included in a motion candidate list generated for the current video block.

[0153] Clause 32. The method of any of clauses 23-31, wherein the current video block is encoded and decoded using one of: intra template matching, IBC AMVP, or IBC merging.

[0154] Clause 33. The method of any of clauses 23-24, wherein the at least one video block is adjacent to the current video block, and the information is determined based on a predefined rule associated with encoded information of the at least one video block.

[0155] Clause 34. The method of clause 33, wherein a first indication is included in the bitstream and indicates that the current video block is encoded using intra template matching.

[0156] Clause 35. A method according to clause 33, wherein if the first indication indicates that the current video block is encoded and decoded using intra-frame template matching, the information includes how to adjust the multiple samples, and a syntax element indicating whether the adjustment process is applied to the multiple samples is included in the bitstream.

[0157] Clause 36. A method according to clause 33, wherein if the first indication indicates that the current video block is encoded and decoded using intra-frame template matching, the information includes whether the adjustment process is applied to the multiple samples, and a syntax element indicating how to adjust the multiple samples is included in the bitstream.

[0158] Clause 37. The method of any one of clauses 34-36, wherein the first indication is an intra template match flag.

[0159] Clause 38. The method of clause 33, wherein a second indication is included in the bitstream and indicates that the current video block is encoded with IBC AMVP.

[0160] Clause 39. A method according to clause 33, wherein if the second indication indicates that the current video block is encoded and decoded using IBCAVP, the information includes how to adjust the multiple samples, and a syntax element indicating whether the adjustment process is applied to the multiple samples is included in the bitstream.

[0161] Clause 40. A method according to clause 33, wherein if the second indication indicates that the current video block is encoded and decoded with IBCAVP, the information includes whether the adjustment process is applied to the multiple samples, and syntax elements indicating how to adjust the multiple samples are included in the bitstream.

[0162] Clause 41. The method of any of Clauses 38-40, wherein the second indication is an IBC AMVP flag.

[0163] Clause 42. The method of clause 33, wherein a third indication is included in the bitstream and indicates that the current video block is encoded with IBC merging.

[0164] Clause 43. A method according to clause 33, wherein if the third indication indicates that the current video block is encoded and decoded using IBC merging, the information includes how to adjust the multiple samples, and a syntax element indicating whether the adjustment process is applied to the multiple samples is included in the bitstream.

[0165] Clause 44. A method according to clause 33, wherein if a third indication indicates that the current video block is encoded and decoded using IBC merging, the information includes whether the adjustment process is applied to the multiple samples, and a syntax element indicating how to adjust the multiple samples is included in the bitstream.

[0166] Clause 45. The method of any one of clauses 42-44, wherein the third indication is an IBC merge flag.

[0167] Clause 46. The method of any one of clauses 23-45, wherein the information is stored.

[0168] Clause 47. The method of any of Clauses 21-46, wherein another video block of the video different from the current video block is encoded with the information.

[0169] Clause 48. The method of any of Clauses 21-47, wherein the information is stored in at least one buffer.

[0170] Clause 49. The method of clause 48, wherein the at least one buffer comprises one of: at least one line buffer, a table, a picture buffer, a compressed picture buffer, or a temporal buffer.

[0171] Clause 50. A method according to any of clauses 21-48, wherein the information is stored in a historical motion vector table.

[0172] Clause 51. The method of clause 50, wherein the historical motion vector table is a HMVP table.

[0173] Clause 52. The method of any of clauses 1-51, wherein codec information of the current video block is stored for use in determining a context of a syntax element associated with the adaptation process.

[0174] Clause 53. A method according to clause 20 or 52, wherein the coding information of the video block includes at least one of the following: information about whether the adjustment process is applied to the samples of the video block, information about how to adjust the samples of the video block, block availability, prediction mode for the video block; information about whether the video block is merged coded or decoded, or information about whether the video block is IBC coded or decoded.

[0175] Clause 54. The method of any of clauses 1-22 and 24-53, 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.

[0176] Clause 55. A method according to any of clauses 1-53, wherein whether and / or how to apply the method is indicated at one of: sequence level, group of picture level, picture level, slice level, or tile group level.

[0177] Clause 56. A method according to any one of clauses 1-53, wherein whether and / or how the method is applied 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.

[0178] Clause 57. A method according to any of clauses 1-53, wherein whether and / or how to apply the method is indicated at an area containing more than one sample or pixel.

[0179] Clause 58. A method according to clause 57, 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.

[0180] Clause 59. The method of any of clauses 1-58, wherein whether and / or how to apply the method depends on the encoded information.

[0181] Clause 60. The method of clause 59, wherein the encoded information comprises at least one of: block size, color format, single or double tree partitioning, double tree partitioning, color component, slice type, or picture type.

[0182] Clause 61. The method of any of clauses 1-60, wherein the converting comprises encoding the current video block into the bitstream.

[0183] Clause 62. The method of any of clauses 1-60, wherein the converting comprises decoding the current video block from the bitstream.

[0184] Clause 63. 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 of clauses 1-62.

[0185] Clause 64. A non-transitory computer-readable storage medium storing instructions for causing a processor to perform the method of any of clauses 1-62.

[0186] Clause 65. A non-transitory computer-readable recording medium storing a bitstream of a video generated by a method performed by a device for video processing, wherein the method comprises: performing a conversion between a current video block of the video and the bitstream, wherein a first syntax element is included in the bitstream and indicates whether an adjustment process is applied to multiple samples of the current video block.

[0187] Clause 66. A method for storing a bitstream of a video, comprising: performing a conversion between a current video block of the video and the bitstream; and storing the bitstream in a non-transitory computer-readable recording medium, wherein a first syntax element is included in the bitstream and indicates whether an adjustment process is applied to multiple samples of the current video block.

[0188] Clause 67. A non-transitory computer-readable recording medium storing a bitstream of a video generated by a method performed by a device for video processing, wherein the method comprises: determining information about an adjustment process of adjusting samples of a video block for a current video block of the video based on at least one video block of the video, wherein the at least one video block is encoded and decoded before the current video block; and generating the bitstream based on the information.

[0189] Clause 68. A method for storing a bitstream of a video, comprising: determining, for a current video block of the video, information about an adjustment process for adjusting samples of a video block based on at least one video block of the video, wherein the at least one video block is encoded and decoded before the current video block; generating the bitstream based on the information; and storing the bitstream in a non-transitory computer-readable recording medium. Example Device

[0190] 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).

[0191] 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.

[0192] 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.

[0193] 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.).

[0194] 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.

[0195] 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.

[0196] 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.

[0197] 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.

[0198] 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).

[0199] 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.

[0200] 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.

[0201] 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.

[0202] 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.

[0203] 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: A conversion is performed between a current video block of a video and a bitstream of the video, wherein a first syntax element is included in the bitstream and indicates whether an adjustment process is applied to a plurality of samples of the current video block.

2. The method according to claim 1, wherein the adjustment process comprises at least one of the following: reordering the plurality of samples, Flipping the multiple samples, moving the multiple samples, rotating the plurality of samples, or A transformation is performed on the plurality of samples.

3. The method according to any one of claims 1-2, wherein the current video block is encoded and decoded using a prediction scheme.

4. The method according to claim 3, wherein the prediction scheme comprises one of the following: Intra-frame template matching, Intra Block Copy (IBC) Advanced Motion Vector Prediction (AMVP), or IBC merger.

5. The method according to any one of claims 1 to 4, wherein a first indication is included in the bitstream and indicates that the current video block is encoded and decoded using intra template matching.

6. The method according to any one of claims 1-4, wherein a second indication is included in the bitstream and indicates that the current video block is coded with IBC AMVP.

7. The method according to any one of claims 1-4, wherein a third indication is included in the bitstream and indicates that the current video block is encoded and decoded using IBC merging.

8. The method according to any one of claims 1 to 7, wherein a second syntax element indicating how to adjust the plurality of samples is included in the bitstream.

9. The method according to any one of claims 1-8, wherein a single syntax element indicating the type of the adaptation process is included in the bitstream.

10. The method of any one of claims 1-8, wherein if a first indication indicates that the current video block is encoded and decoded using intra template matching, a single syntax element indicating the type of the adaptation process is included in the bitstream. The method according to claim 5 or 10, wherein the first indication is an intra-frame template matching use flag.

12. The method of any one of claims 1-8, wherein if a second indication indicates that the current video block is coded with IBC AMVP, a single syntax element indicating a type of the adaptation process is included in the bitstream.

13. The method of claim 6 or 12, wherein the second indication is an IBC AMVP flag.

14. The method of any one of claims 1-8, wherein if a third indication indicates that the current video block is encoded with IBC merging, a single syntax element indicating the type of the adjustment process is included in the bitstream.

15. The method according to claim 7 or 14, wherein the third indication is an IBC merge flag.

16. The method according to any one of claims 1-15, wherein the first syntax element further indicates how to adjust the plurality of samples.

17. The method according to any one of claims 1-16, wherein the first value of the first syntax element indicates that the adjustment process is not applied to the plurality of samples; A second value of the first syntax element indicates that a first type of adjustment process is applied to the plurality of samples; and A third value of the first syntax element indicates that a second type of adjustment process is applied to the plurality of samples.

18. The method according to any one of claims 1-17, wherein at least one syntax element associated with the adaptation process is context-coded. The method of claim 18 , wherein the at least one syntax element comprises the first syntax element.

20. The method according to any one of claims 18-19, wherein a context for encoding and decoding the at least one syntax element depends on encoding and decoding information of at least one neighboring block or at least one neighboring sample of the current video block.

21. The method according to any one of claims 1-20, wherein information about the adjustment process is stored.

22. The method according to claim 21, wherein the information includes at least one of the following: Whether the adjustment process is applied to multiple samples of the current video block, or How to adjust the number of samples.

23. A method for video processing, comprising: For a conversion between a current video block of a video and a bitstream of the video, determining information about an adjustment process for adjusting samples of the video block based on at least one video block of the video, the at least one video block being encoded and decoded before the current video block; and The converting is performed based on the information.

24. The method of claim 23, wherein the information includes at least one of: Whether the adjustment process is applied to multiple samples of the current video block, or How to adjust the number of samples.

25. The method of any one of claims 23-24, wherein if the adjustment process is applied to samples of the at least one video block, the adjustment process is applied to multiple samples of the current video block, or If the adjustment process is applied to samples of the at least one video block, the adjustment process is applied to multiple samples of the current video block, and the multiple samples of the current video block are adjusted in the same manner as the samples of the at least one video block.

26. The method of any one of claims 23-25, wherein the at least one video block comprises at least one of: A neighboring video block adjacent to the current video block; or Neighboring video blocks that are not adjacent to the current video block.

27. The method of any of claims 23-25, wherein the at least one video block is included in a history-based motion table for the current video block.

28. The method of claim 27, wherein the history-based motion table is a history-based motion vector prediction (HMVP) table.

29. The method of any of claims 23-25, wherein the at least one video block is a temporal motion candidate for the current video block.

30. The method of any one of claims 23-25, wherein the at least one video block is included in an IBC merge candidate list or an IBC AMVP candidate list for the current video block.

31. The method of any one of claims 23-25, wherein the at least one video block is included in a motion candidate list generated for the current video block.

32. The method of any one of claims 23-31, wherein the current video block is encoded or decoded using one of: Intra-frame template matching, IBC AMVP, or IBC merger.

33. The method of any of claims 23-24, wherein the at least one video block is adjacent to the current video block, and the information is determined based on a predefined rule associated with encoded information of the at least one video block.

34. The method of claim 33, wherein a first indication is included in the bitstream and indicates that the current video block is encoded using intra template matching.

35. The method of claim 33, wherein if the first indication indicates that the current video block is encoded and decoded using intra template matching, the information includes how to adjust the multiple samples, and a syntax element indicating whether the adjustment process is applied to the multiple samples is included in the bitstream.

36. The method of claim 33, wherein if the first indication indicates that the current video block is encoded and decoded using intra template matching, the information includes whether the adjustment process is applied to the plurality of samples, and a syntax element indicating how to adjust the plurality of samples is included in the bitstream.

37. The method according to any one of claims 34-36, wherein the first indication is an intra template matching flag.

38. The method of claim 33, wherein a second indication is included in the bitstream and indicates that the current video block is coded with IBC AMVP.

39. The method of claim 33, wherein if the second indication indicates that the current video block is encoded and decoded with IBCAVP, the information includes how to adjust the multiple samples, and a syntax element indicating whether the adjustment process is applied to the multiple samples is included in the bitstream.

40. The method of claim 33, wherein if the second indication indicates that the current video block is encoded and decoded with IBCAVP, the information includes whether the adjustment process is applied to the plurality of samples, and a syntax element indicating how to adjust the plurality of samples is included in the bitstream.

41. The method of any one of claims 38-40, wherein the second indication is an IBC AMVP flag.

42. The method of claim 33, wherein a third indication is included in the bitstream and indicates that the current video block is encoded with IBC merging.

43. The method of claim 33, wherein if a third indication indicates that the current video block is encoded and decoded with IBC merging, the information includes how to adjust the plurality of samples, and a syntax element indicating whether the adjustment process is applied to the plurality of samples is included in the bitstream.

44. The method of claim 33, wherein if a third indication indicates that the current video block is encoded with IBC merging, the information includes whether the adjustment process is applied to the plurality of samples, and syntax elements indicating how to adjust the plurality of samples are included in the bitstream.

45. The method of any one of claims 42-44, wherein the third indication is an IBC merge flag.

46. ​​A method according to any one of claims 23-45, wherein the information is stored.

47. The method of any one of claims 21-46, wherein another video block of the video different from the current video block is encoded and decoded using the information.

48. The method of any one of claims 21-47, wherein the information is stored in at least one buffer.

49. The method of claim 48, wherein the at least one buffer comprises one of: at least one line buffer, surface, Image buffering, A compressed image buffer, or Time domain buffering.

50. The method of any one of claims 21-48, wherein the information is stored in a historical motion vector table.

51. The method of claim 50, wherein the historical motion vector table is a HMVP table.

52. The method of any one of claims 1-51, wherein codec information of the current video block is stored for use in determining a context of a syntax element associated with the adjustment process.

53. The method according to claim 20 or 52, wherein the codec information of the video block comprises at least one of the following: information about whether the adjustment process is applied to samples of the video block, information on how to adjust the samples of said video block, Block availability, a prediction mode for the video block; Information about whether the video block is merged or not, or Information about whether the video block is IBC coded.

54. The method of any one of claims 1-22 and 24-53, 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.

55. The method of any one of claims 1-53, wherein whether 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.

56. The method according to any one of claims 1-53, wherein whether and / or how to apply the method is indicated in one of: 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.

57. A method according to any one of claims 1-53, wherein whether and / or how to apply the method is indicated at an area containing more than one sample or pixel.

58. The method of claim 57, 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, Tile, or Sub-picture.

59. The method according to any one of claims 1-58, wherein whether and / or how to apply the method depends on the encoded information.

60. The method of claim 59, wherein the encoded information includes at least one of: Block size, Color format, Single and double tree partitioning, Double tree partitioning, Color components, Strip type, or Image type.

61. The method of any one of claims 1-60, wherein the converting comprises encoding the current video block into the bitstream.

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

63. An apparatus for video processing, comprising a processor and a non-volatile memory having instructions thereon, wherein the instructions, when executed by the processor, cause the processor to perform the method of any one of claims 1-62.

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

65. A non-transitory computer-readable recording medium storing a bitstream of a video generated by a method performed by an apparatus for video processing, wherein the method comprises: performing a conversion between a current video block of the video and the bitstream, Wherein a first syntax element is included in the bitstream and indicates whether an adjustment process is applied to a plurality of samples of the current video block.

66. A method for storing a bitstream of a video, comprising: performing a conversion between a current video block of the video and the bitstream; as well as storing the bitstream in a non-transitory computer-readable recording medium, Wherein a first syntax element is included in the bitstream and indicates whether an adjustment process is applied to a plurality of samples of the current video block.

67. A non-transitory computer-readable recording medium storing a bitstream of a video generated by a method performed by an apparatus for video processing, wherein the method comprises: Determining, for a current video block of the video, information about an adjustment process for adjusting samples of the video block based on at least one video block of the video, the at least one video block being encoded and decoded before the current video block; and The bitstream is generated based on the information.

68. A method for storing a bitstream of a video, comprising: Determining, for a current video block of the video, information about an adjustment process for adjusting samples of the video block based on at least one video block of the video, the at least one video block being encoded and decoded before the current video block; generating the bitstream based on the information; as well as The bit stream is stored in a non-transitory computer-readable recording medium.

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