Method and device for video processing and medium

Abstract

Embodiments of the present disclosure provide a solution for video processing. A method for video processing is presented. The method includes, for a conversion between a video unit of the video and a bitstream of the video, determining a candidate list for the video unit based on one or more non-adjacent video units of the video unit, where the candidate list is an Intra Block Copy (IBC) candidate list or an Intra Template Matching Prediction (IntraTMP) candidate list, wherein the position order of one or more non-adjacent video units is predefined or based on coding and decoding information; and performing a conversion based on the candidate list.

Description

Technical Field

[0001] The embodiments of this disclosure generally relate to video processing techniques, and more specifically, to template matching for intra-frame block copying. Background Technology

[0002] Today, digital video capabilities are being applied to all aspects of people's lives. Various video compression technologies have been proposed for video encoding / decoding, such as MPEG-2, MPEG-4, ITU-TH.263, ITU-TH.264 / MPEG-4 Part 10 Advanced Video Codec (AVC), ITU-TH.265 High Efficiency Video Codec (HEVC) standard, and Multi-Functional Video Codec (VVC) standard. However, the encoding and decoding efficiency of video encoding and decoding technologies is generally expected to be further improved. Summary of the Invention

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

[0004] In a first aspect, a method for video processing is proposed. This method includes: a conversion between video units and a video bitstream for a given video unit; determining a candidate list for the video unit based on one or more non-adjacent video units, wherein the candidate list is an intra-block copy (IBC) candidate list or an intra-template matching prediction (IntraTMP) candidate list, and the positional order of the one or more non-adjacent video units is predefined or based on encoding / decoding information; and performing the conversion based on the candidate list. In this manner, template matching for IBC is enhanced, thereby improving encoding / decoding efficiency and performance.

[0005] In a second aspect, an apparatus for video processing is provided. The apparatus includes a processor and a non-transitory memory having instructions thereon. When executed by the processor, the instructions cause the processor to perform the method according to the first aspect of this disclosure.

[0006] In a third aspect, a non-transitory computer-readable storage medium is proposed. This non-transitory computer-readable storage medium stores instructions that cause a processor to execute the method according to the first aspect of this disclosure.

[0007] In a fourth aspect, another non-transitory computer-readable recording medium is proposed. This non-transitory computer-readable recording medium stores a bitstream of video generated by a method performed by an apparatus for video processing. The method includes: determining a candidate list for video units based on one or more non-adjacent video units, wherein the candidate list is an intra-block copy (IBC) candidate list or an intra-template matching prediction (IntraTMP) candidate list, and the positional order of the one or more non-adjacent video units is predefined or based on encoding / decoding information; and generating a bitstream based on the candidate list.

[0008] In the fifth aspect, a method for storing a bitstream of video is proposed. The method includes: determining a candidate list for video units based on one or more non-adjacent video units, wherein the candidate list is an intra-block copy (IBC) candidate list or an intra-template matching prediction (IntraTMP) candidate list, and the positional order of the one or more non-adjacent video units is predefined or based on encoding / decoding information; generating a bitstream based on the candidate list; and storing the bitstream in a non-transitory computer-readable recording medium.

[0009] This summary aims to present, in a simplified form, the selected concepts further described below in the detailed embodiments. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. Attached Figure Description

[0010] The above and other objects, features, and advantages of exemplary embodiments of the present disclosure will become more apparent from 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.

[0011] Figure 1 A block diagram of an example video codec system according to some embodiments of the present disclosure is shown; Figure 2 A block diagram of a first example video encoder according to some embodiments of the present disclosure is shown; Figure 3 A block diagram of an example video decoder according to some embodiments of the present disclosure is shown; Figure 4 An example of a VVC encoder block diagram is shown; Figure 5 67 intra-frame prediction modes are shown; Figure 6A and Figure 6B Reference samples for wide-angle intra-frame prediction are shown; Figure 7 The discontinuity problem is shown when the orientation exceeds 45°; Figure 8A and Figure 8B The MMVD search point is shown; Figure 9 A schematic diagram for the symmetric MVD mode is shown; Figure 10 The extended CU region used in BDOF is shown; Figure 11 The top and left neighbor blocks used in the CIIP weight derivation are shown; Figure 12A and Figure 12B An affine motion model based on control points is shown; Figure 13 The affine MVF for each sub-block is shown; Figure 14 The location of the inherited affine motion prediction value is shown; Figure 15 This demonstrates the inheritance of control point motion vectors; Figure 16 The locations of candidate positions for the constructed affine Merge pattern are shown; Figure 17 A schematic diagram illustrating the use of motion vectors for the proposed combination method is shown; Figure 18 The sub-block MV VSB and pixel Δv(i,j) are shown (red arrows); Figure 19A and Figure 19B The SbTMVP procedure in VVC is shown; Figure 20 Local lighting compensation is shown; Figure 21 This indicates that no downsampling was performed on the short side; Figure 22 This shows the refinement of motion vectors on the decoding side; Figure 23 The diamond-shaped area in the search region is shown; Figure 24 The locations of the spatial merge candidates are shown; Figure 25 The candidate pairs considered for redundancy checks of spatial merge candidates are shown. Figure 26 A schematic diagram of motion vector scaling for temporal Merge candidates is shown; Figure 27 The candidate positions, C0 and C1, for the time-domain Merge candidate are shown; Figure 28 The VVC spatial neighboring blocks of the current block are shown; Figure 29A schematic diagram of the virtual block in the i-th round of search is shown; Figure 30 An example of GPM partitioning grouped at the same angle is shown; Figure 31 The unidirectional prediction MV selection for geometric segmentation patterns is shown; Figure 32 The bending weights using the geometric segmentation pattern are shown. An example of generation; Figure 33 The spatial neighboring blocks used to derive spatial merge candidates are shown; Figure 34 This demonstrates performing template matching on the search area surrounding the initial MV; Figure 35 A schematic diagram of a sub-block applying OBMC is shown; Figure 36 The location, type, and transformation type of the SBT are shown; Figure 37 The neighboring samples used to calculate SAD are shown; Figure 38 The neighboring samples used to calculate SAD for sub-CU level motion information are shown; Figure 39 The sorting process is shown; Figure 40 The reordering process in the encoder is shown; Figure 41 The reordering process in the decoder is shown; Figure 42 The first HPT and the second HPT are shown; Figure 43A and Figure 43B The spatial nearest neighbor is shown for deriving affine Merge / AMVP candidates; Figure 44 A schematic diagram of affine Merge / AMVP candidates, from non-nearest neighbors to the first type of construction, is shown. Figure 45 The IBC reference area is shown, depending on the current CU location; Figure 46 An example of symmetry is shown in a screen content image; Figure 47A A schematic diagram of BV adjustment for horizontal flipping is shown; Figure 47B A schematic diagram of BV adjustment for vertical flipping is shown; Figure 48 The intra-frame template matching search area used is shown; Figure 49A schematic diagram of the template area is shown; Figure 50 The ramp function for weighting GPM mixing is shown based on the displacement (d) from the predicted sample location to the GPM segmentation boundary and the mixing region size (τ). Figure 51 GPM with inter-frame and intra-frame prediction is shown; Figure 52 The edges on the template are shown; Figure 53 The spatial portion of the convolution filter is shown; Figure 54 The reference region (and its padding) used to derive the filter coefficients is shown. Figure 55 Four Sobel-based gradient modes for GLM are shown; Figure 56 This shows that the unreconstructed samples (shaded) in the reference block are filled by replicating their predicted samples; Figure 57 Several rhombus shapes used for template matching are shown; Figure 58 A flowchart of a method for video processing according to embodiments of the present disclosure is shown; and Figure 59 A block diagram of a computing device in which various embodiments of the present disclosure may be implemented is shown.

[0012] In all accompanying drawings, the same or similar reference numerals usually refer to the same or similar elements. Detailed Implementation

[0013] The principles of this disclosure will now be described with reference to some embodiments. It should be understood that these embodiments are described for illustrative purposes only and to help those skilled in the art understand and implement this disclosure, and do not imply any limitation on the scope of this disclosure. In addition to the methods described below, the disclosure described herein can be implemented in various other ways.

[0014] In the following description and claims, unless otherwise defined, all scientific and technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0015] The terms "an embodiment," "embodiment," "example embodiment," etc., used in this disclosure refer to embodiments that may include specific features, structures, or characteristics, but not every embodiment is required to include that specific feature, structure, or characteristic. Furthermore, these phrases do not necessarily refer to the same embodiment. Additionally, when a specific feature, structure, or characteristic is described in conjunction with an example embodiment, whether explicitly described or not, it is believed that such a feature, structure, or characteristic affecting its relation to other embodiments is within the knowledge of those skilled in the art.

[0016] 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 used only to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may 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.

[0017] The terminology used herein is for the purpose of describing particular embodiments only and is 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 “comprising,” “including,” and / or “having” as used herein indicate the presence of the said features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0018] Example Environment Figure 1 This is a block diagram illustrating an example video encoding / decoding system 100 from which the techniques of this disclosure may be utilized. As shown, the video encoding / decoding 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.

[0019] Video source 112 may include sources such as video capture devices. Examples of video capture devices include, but are not limited to, interfaces for receiving video data from video content providers, computer graphics systems for generating video data, and / or combinations thereof.

[0020] Video data may include one or more images. Video encoder 114 encodes the video data from video source 112 to generate a bitstream. The bitstream may include a sequence of bits forming an encoded representation of the video data. The bitstream may include encoded images and associated data. An encoded image is an encoded representation of an image. Associated data may include sequence parameter sets, image parameter sets, and other syntax structures. I / O interface 116 may include a modulator / demodulator and / or a transmitter. Encoded video data can be directly transmitted to destination device 120 via network 130A through I / O interface 116. Encoded video data may also be stored on storage medium / server 130B for access by destination device 120.

[0021] 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 acquire 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 a user. The display device 122 may be integrated with the destination device 120, or it may be external to the destination device 120, which is configured to interface with an external display device.

[0022] The video encoder 114 and the video decoder 124 can operate according to video compression standards, such as the High Efficiency Video Codec (HEVC) standard, the Multi-Functional Video Codec (VVC) standard, and other existing and / or future standards.

[0023] Figure 2 This is a block diagram illustrating an example of a video encoder 200 according to some embodiments of the present disclosure. The video encoder 200 may be... Figure 1 An example of a video encoder 114 in system 100 is shown.

[0024] The video encoder 200 can be configured to implement any or all of the technologies disclosed herein. Figure 2 In the example, the video encoder 200 includes multiple functional components. The techniques described in this disclosure can be shared among the various components of the video encoder 200. In some examples, the processor can be configured to perform any or all of the techniques described in this disclosure.

[0025] In some embodiments, the video encoder 200 may include a segmentation unit 201, a prediction unit 202, a residual generation unit 207, a transform unit 208, a quantization unit 209, an inverse quantization unit 210, an inverse transform unit 211, a reconstruction unit 212, a buffer 213, and an entropy coding unit 214. 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.

[0026] 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 can perform prediction in an IBC mode in which at least one reference picture is the picture containing the current video block.

[0027] Furthermore, although some components (such as motion estimation unit 204 and motion compensation unit 205) can be integrated, for interpretable purposes, these components are... Figure 2 The examples are shown separately.

[0028] The segmentation unit 201 can segment an image into one or more video blocks. The video encoder 200 and the video decoder 300 can support various video block sizes.

[0029] The mode selection unit 203 can, for example, select one of several coding modes (intra-coding or inter-coding) based on the error result, and provide the resulting intra-coded or inter-coded block to the residual generation unit 207 to generate residual block data, and to the reconstruction unit 212 to reconstruct the coded block for use as a reference image. In some examples, the mode selection unit 203 can select an intra-inter-prediction joint prediction (CIIP) mode, in which prediction is based on inter-prediction signals and intra-prediction signals. In the case of inter-prediction, the mode selection unit 203 can also select a resolution for the block based on the motion vector (e.g., sub-pixel precision or integer pixel precision).

[0030] To perform inter-frame prediction on the current video block, motion estimation unit 204 can generate motion information for the current video block by comparing one or more reference frames from buffer 213 with the current video block. Motion compensation unit 205 can determine the predicted video block for the current video block based on the motion information and decoded samples of images from buffer 213 other than the image associated with the current video block.

[0031] The motion estimation unit 204 and the motion compensation unit 205 can perform different operations on the current video block, for example, depending on whether the current video block is in an I-strip, P-strip, or B-strip. As used herein, an "I-strip" can refer to a portion of an image composed of macroblocks, all of which are based on macroblocks within the same image. Furthermore, as used herein, in some aspects, "P-strip" and "B-strip" can refer to portions of an image composed of macroblocks independent of macroblocks within the same image.

[0032] In some examples, motion estimation unit 204 can perform unidirectional prediction on the current video block, and can search reference images in list 0 or list 1 to find a reference video block for the current video block. Motion estimation unit 204 can then generate a reference index indicating the reference image containing the reference video block in list 0 or list 1, and a motion vector indicating the spatial displacement between the current video block and the reference video block. Motion estimation unit 204 can output the reference index, prediction direction indicator, and motion vector as motion information for the current video block. Motion compensation unit 205 can 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.

[0033] Alternatively, in other examples, motion estimation unit 204 can perform bidirectional prediction on the current video block. Motion estimation unit 204 can search reference images in list 0 to find a reference video block for the current video block, and can also search reference images in list 1 to find another reference video block for the current video block. Motion estimation unit 204 can then generate multiple reference indices and multiple motion vectors, the multiple reference indices indicating reference images containing multiple reference video blocks in lists 0 and 1, and the multiple motion vectors indicating multiple spatial displacements between the multiple reference video blocks and the current video block. Motion estimation unit 204 can output the multiple reference indices and multiple motion vectors of the current video block as motion information for the current video block. Motion compensation unit 205 can generate a predicted video block for the current video block based on the multiple reference video blocks indicated by the motion information of the current video block.

[0034] In some examples, the motion estimation unit 204 can output a complete set of motion information for use in the decoder's decoding process. Alternatively, in some embodiments, the motion estimation unit 204 can reference the motion information of another video block to transmit the motion information of the current video block via a signal. For example, the motion estimation unit 204 can determine that the motion information of the current video block is sufficiently similar to the motion information of neighboring video blocks.

[0035] In one example, the motion estimation unit 204 may indicate a value in the syntax structure associated with the current video block that indicates to the video decoder 300 that the current video block has the same motion information as another video block.

[0036] In another example, motion estimation unit 204 can identify another video block and motion vector difference (MVD) in the 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. Video decoder 300 can use the motion vector of the indicated video block and the motion vector difference to determine the motion vector of the current video block.

[0037] As discussed above, the video encoder 200 can transmit motion vectors via signals in a predictive manner. Two examples of predictive signaling techniques that can be implemented by the video encoder 200 include Advanced Motion Vector Prediction (AMVP) and Merge Pattern Signaling.

[0038] Intra-prediction unit 206 can perform intra-prediction on the current video block. When intra-prediction unit 206 performs intra-prediction on the current video block, it can generate prediction data for the current video block based on decoded samples from other video blocks in the same frame. The prediction data for the current video block can include the predicted video block and various syntax elements.

[0039] The residual generation unit 207 can generate residual data for the current video block by subtracting (e.g., indicated by a minus sign) multiple predicted video blocks from the current video block. The residual data for the current video block may include residual video blocks corresponding to different sample components of the samples in the current video block.

[0040] In other examples, such as in skip mode, residual data for the current video block may not exist, and residual generation unit 207 may not perform a subtraction operation.

[0041] The transform processing unit 208 can generate one or more transform coefficient video blocks for the current video block by applying one or more transforms to the residual video blocks associated with the current video block.

[0042] After the transform processing unit 208 generates a transform coefficient video block associated with the current video block, the quantization unit 209 can 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.

[0043] The inverse quantization unit 210 and the inverse transform unit 211 can apply inverse quantization and inverse transform to the transform coefficient video block respectively to reconstruct the residual video block from the transform coefficient video block. The reconstruction unit 212 can add the reconstructed residual video block to the corresponding samples of one or more predicted video blocks generated by the prediction unit 202 to produce a reconstructed video block associated with the current video block for storage in the buffer 213.

[0044] After the video block is reconstructed by reconstruction unit 212, a loop filtering operation can be performed to reduce video block artifacts in the video block.

[0045] Entropy encoding unit 214 can receive data from other functional components of video encoder 200. When entropy encoding unit 214 receives data, it can perform one or more entropy encoding operations to generate entropy-encoded data and output a bitstream including the entropy-encoded data.

[0046] Figure 3 This is a block diagram illustrating an example of a video decoder 300 according to some embodiments of the present disclosure. The video decoder 300 may be... Figure 1 An example of video decoder 124 in system 100 is shown.

[0047] The video decoder 300 can be configured to perform any or all of the technologies disclosed herein. Figure 3 In the example, the video decoder 300 includes multiple functional components. The techniques described in this disclosure can be shared among the various components of the video decoder 300. In some examples, the processor can be configured to perform any or all of the techniques described in this disclosure.

[0048] exist Figure 3 In the example, the video decoder 300 includes an entropy decoding unit 301, a motion compensation unit 302, an intra-frame prediction unit 303, an inverse quantization unit 304, an inverse transform unit 305, a reconstruction unit 306, and a buffer 307. In some examples, the video decoder 300 can perform a decoding process that is generally contrasted with the encoding process described with respect to the video encoder 200.

[0049] Entropy decoding unit 301 can retrieve the encoded bitstream. The encoded bitstream may include entropy-encoded video data (e.g., encoded blocks of video data). Entropy decoding unit 301 can decode the entropy-encoded video data, and based on the entropy-encoded video data, motion compensation unit 302 can determine motion information, including motion vectors, motion vector precision, reference picture list indices, and other motion information. Motion compensation unit 302 can determine such information, for example, by performing AMVP and Merge mode. AMVP is used, which involves deriving several most likely candidates based on data from neighboring PBs and reference pictures. Motion information typically includes horizontal motion vector displacement values ​​and vertical motion vector displacement values, one or two reference picture indices, and, in the case of a prediction region in a B-strip, an identifier 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 spatially or temporally neighboring blocks.

[0050] The motion compensation unit 302 can generate motion compensation blocks and can perform interpolation based on an interpolation filter. Identifiers for interpolation filters used with sub-pixel precision can be included in the syntax elements.

[0051] The motion compensation unit 302 can use the interpolation filter used by the video encoder 200 during the encoding of the video block to calculate the interpolated values ​​for sub-integer pixels of the reference block. The motion compensation unit 302 can determine the interpolation filter used by the video encoder 200 based on the received syntax information, and the motion compensation unit 302 can use the interpolation filter to generate the prediction block.

[0052] Motion compensation unit 302 may use at least some of the syntax information to determine the size of the blocks used to encode (multiple) frames and / or (multiple) stripes of the encoded video sequence, segmentation information describing how each macroblock of the image of the encoded video sequence is segmented, a pattern indicating how each segment is encoded, one or more reference frames (and a list of reference frames) for each inter-frame coded block, and other information for decoding the encoded video sequence. As used herein, in some aspects, a “strip” can refer to a data structure that can be decoded independently of other stripes of the same image in terms of entropy encoding / decoding, signal prediction, and residual signal reconstruction. A strip can be an entire image or a region of an image.

[0053] Intra-prediction unit 303 can use, for example, an intra-prediction mode received in the bitstream to form prediction blocks from spatially adjacent blocks. Dequantization unit 304 dequantizes (i.e., dequantizes) the quantized video block coefficients provided in the bitstream and decoded by entropy decoding unit 301. Inverse transform unit 305 applies the inverse transform.

[0054] The reconstruction unit 306 can 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-frame prediction unit 303. If necessary, a deblocking filter can also be used to filter the decoded block to remove block artifacts. The decoded video block is then stored in a buffer 307, which provides a reference block for subsequent motion compensation / intra-frame prediction and also generates decoded video for presentation on a display device.

[0055] Some exemplary embodiments of this disclosure will be described in detail below. It should be understood that section headings are used in this document for ease of understanding and not to limit the embodiments disclosed in a section to that section only. Furthermore, while some embodiments are described with reference to multi-functional video codecs or other specific video codecs, the disclosed techniques are also applicable to other video codec techniques. Additionally, although some embodiments describe video encoding and decoding steps in detail, it will be understood that the corresponding decoding steps for decoding will be implemented by the decoder. Furthermore, the term "video processing" includes video encoding / decoding or compression, video decoding or decompression, and video transcoding, in which video pixels are represented from one compression format to another or at different compression bitrates.

[0056] 1. Brief Overview This disclosure relates to video codec techniques. Specifically, it relates to intra-block copying (IBC), how and / or whether to apply template matching to IBC, how to construct a candidate list of IBCs, and other codec tools in image / video codecs. This disclosure can be applied to existing video codec standards such as HEVC or VVC. It may also be applicable to future video codec standards or video codecs.

[0057] 2. Introduction Video codec standards have primarily evolved through the development of well-known ITU-T and ISO / IEC standards. ITU-T developed the H.261 and H.263 standards, while ISO / IEC developed MPEG-1 and MPEG-4 visual standards. These two organizations jointly developed the H.262 / MPEG-2 video standard, the H.264 / MPEG-4 Advanced Video Codec (AVC) standard, and the H.265 / HEVC standard. Starting with H.262, video codec standards are based on a hybrid video codec architecture, utilizing temporal prediction plus transform coding. To explore future video codec technologies beyond HEVC, the Joint Video Exploration Team (JVET) was jointly established by VCEG and MPEG in 2015. Since then, JVET has adopted many new methods and incorporated them into a reference software called the Joint Exploration Model (JEM). In April 2018, the Joint Video Experts Group (JVET) between VCEG (Q6 / 16) and ISO / IEC JTC1 SC29 / WG11 (MPEG) was established to work on the VVC standard, with the goal of reducing the bit rate by 50% compared to HEVC.

[0058] 2.1. Encoder / decoder streams of typical video codecs Figure 4 An example of a VVC encoder block diagram is shown, comprising three loop filtering blocks: Deblocking Filter (DF), Sample Adaptive Compensation (SAO), and ALF. Unlike DF, which uses predefined filters, SAO and ALF utilize the original samples of the current image, reducing the mean square error between the original and reconstructed samples by adding an offset and applying a Finite Impulse Response (FIR) filter, respectively, and by using encoded / decoded side information through signal transmission offset and filter coefficients. ALF is located in the final processing stage of each image and can be viewed as a tool attempting to capture and repair artifacts caused by previous stages.

[0059] 2.2. Intra-mode encoding and decoding using 67 intra-prediction modes To capture arbitrary edge directions presented in natural videos, such as Figure 5 As shown, the number of directional intra-prediction modes has been expanded from 33 used in HEVC to 65, while the planar and DC modes remain unchanged. These denser directional intra-prediction modes are applicable to all block sizes and both luma and chroma intra-prediction.

[0060] In HEVC, each intra-coded block has a square shape, and the length of each side is a power of 2. Therefore, no division is needed to generate intra-prediction values ​​using DC mode. In VVC, blocks can have rectangular shapes, which generally requires division for each block. To avoid division for DC prediction, only the longer sides are used to calculate the average of non-square blocks.

[0061] 2.2.1. Wide-angle intra-frame prediction Although 67 modes are defined in VVC, the precise prediction direction for a given intra-prediction mode index depends on the block shape. Regular angular intra-prediction directions are defined clockwise from 45 degrees to -135 degrees. In VVC, for non-square blocks, several regular angular intra-prediction modes are adaptively replaced with wide-angle intra-prediction modes. The replaced modes are transmitted via signaling using the original mode index, which is then remapped to the wide-angle mode index after resolution. The total number of intra-prediction modes remains unchanged at 67, and the intra-mode encoding / decoding method remains unchanged.

[0062] To support these predicted directions, a top reference of length 2W+1 and a left reference of length 2H+1 are defined, as follows: Figure 6A and Figure 6B As shown.

[0063] The number of modes replaced in the wide-angle directional mode depends on the block aspect ratio. The replaced intra-prediction modes are shown in Table 2-1.

[0064] Table 2-1 – Intra-prediction modes replaced by wide-angle mode

[0065] like Figure 7 As shown, in the case of wide-angle intra-frame prediction, two vertically adjacent predicted samples can use two non-adjacent reference samples. Therefore, a low-pass reference sample filter and edge smoothing are applied to wide-angle prediction to reduce the increased gap. p α The negative impact of wide-angle mode. If the wide-angle mode represents a non-fractional offset. There are 8 wide-angle modes that satisfy this condition, namely [-14, -12, -10, -6, 72, 76, 78, 80]. When a block is predicted through these modes, the samples in the reference cache are directly copied without applying any interpolation. This modification reduces the number of samples that need to be smoothed. Furthermore, it aligns the design of non-fractional modes in regular prediction modes with that of wide-angle modes.

[0066] In VVC, in addition to 4:2:0, 4:2:2 and 4:4:4 chroma formats are also supported. The chroma derivation mode (DM) derivation table for the 4:2:2 chroma format was originally ported from HEVC, with the number of entries expanded from 35 to 67 to align with the expansion of intra-prediction modes. Since the HEVC specification does not support prediction angles below -135 degrees and above 45 degrees, the luma intra-prediction mode range from 2 to 5 is mapped to 2. Therefore, the chroma DM derivation table for the 4:2:2 chroma format is updated by replacing some values ​​in the mapping table entries to more accurately convert the prediction angles for chroma blocks.

[0067] 2.3. Inter-frame prediction For each inter-frame prediction CU, motion parameters consist of a motion vector, a reference picture index, and a reference picture list usage index, along with additional information required for new encoding / decoding features in the VVC that has been used for inter-frame prediction sample generation. Motion parameters can be transmitted via signaling in an explicit or implicit manner. When a CU is encoded / decoded in skip mode, the CU is associated with a PU and has no significant residual coefficients, no encoded / decoded motion vector increments, or reference picture indices. A Merge mode is defined where motion parameters for the current CU are obtained from neighboring CUs, including spatial and temporal candidates and additional scheduling introduced in the VVC. The Merge mode can be applied to any inter-frame prediction CU, not just skip mode. An alternative to the Merge mode is explicit transmission of motion parameters, where the motion vector for each reference picture list, the corresponding reference picture index, the reference picture list usage flag, and other required information are explicitly transmitted via signaling for each CU.

[0068] 2.4. Intra-Block Copy (IBC) Intra-Block Copy (IBC) is a tool used in the HEVC extension on SCC. It is well known to significantly improve the encoding and decoding efficiency of screen content material. Since IBC mode is implemented as a block-level encoding and decoding mode, block matching (BM) is performed at the encoder to find the optimal block vector (or motion vector) for each CU. Here, the block vector is used to indicate the displacement from the current block to a reference block that has already been reconstructed within the current image. The luma block vector of an IBC-encoded CU is integer precise. The chroma block vector is also rounded to integer precision. When combined with AMVR, IBC mode can switch between 1-pixel motion vector precision and 4-pixel motion vector precision. IBC-encoded CUs are considered a third prediction mode, distinct from intra-frame or inter-frame prediction modes. IBC mode is suitable for CUs with a width and height of 64 luma samples or less.

[0069] On the encoder side, hash-based motion estimation for IBC is performed. The encoder performs RD check on blocks with a width or height no greater than 16 luminance samples. For non-Merge mode, block vector search is first performed using a hash-based search. If the hash search does not return valid candidates, a local search based on block matching is performed.

[0070] In hash-based search, hash key matching (32-bit CRC) between the current block and reference blocks is extended to all allowed block sizes. Hash key calculation for each location in the current image is based on 4x4 sub-blocks. For the larger current block, a hash key match with a reference block is determined when all hash keys of all 4x4 sub-blocks match the hash key at the corresponding reference location. If multiple reference blocks are found to match the hash key of the current block, the block vector cost of each matching reference is calculated, and the one with the lowest cost is selected.

[0071] In block matching search, the search scope is set to cover both the previous CTU and the current CTU.

[0072] At the CU level, the IBC mode is transmitted via signaling using a flag, and it can be transmitted via signaling as IBCAMVP mode or IBC skip / Merge mode, as follows: - IBC Skip / Merge Mode: The Merge candidate index is used to indicate which block vector from the list of neighboring candidate IBC-encoded blocks is used to predict the current block. The Merge list consists of spatial candidates, HMVP candidates, and paired candidates.

[0073] - 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 prediction values, one from the left nearest neighbor and one from the upper nearest neighbor (if IBC encoding / decoding is used). When either nearest neighbor is unavailable, the default block vector is used as the prediction value. A flag is transmitted via signaling to indicate the index of the block vector prediction value.

[0074] 2.5. Merge Pattern with MVD (MMVD) In addition to the Merge mode (where implicitly derived motion information is directly used for generating prediction samples for the current CU), the Merge mode with motion vector difference (MMVD) is introduced in VVC. The MMVD flag is transmitted via signaling immediately after the regular Merge flag is sent to specify whether the MMVD mode is used for the CU.

[0075] In MMVD, after a Merge candidate is selected, it is further refined through MVD information transmitted via signals. This further information includes a Merge candidate flag, an index specifying the amplitude of motion, and an index indicating the direction of motion. In MMVD mode, one of the top two candidates in the Merge list is selected as the MV basis. The MMVD candidate flag is transmitted via signals to specify which candidate to use between the first and second Merge candidates.

[0076] The distance index specifies the motion amplitude information and indicates a predefined offset from the starting point. For example... Figure 8A and Figure 8B As shown, the offset is added to the horizontal or vertical component of the starting MV. The relationship between the distance index and the predefined offset is specified in Table 2-2.

[0077] Table 2-2 – Relationship between Distance Index and Predefined Offset

[0078] The direction index indicates the direction of the MVD relative to the starting point. The direction index can represent four directions, as shown in Table 2-3. It is important to note that the meaning of the MVD sign can vary depending on the information of the starting MV. When the starting MV is a unidirectional or bidirectional prediction MV, and both lists point to the same side of the current image (i.e., both reference POCs are greater than or less than the current image's POC), the signs in Table 2-3 specify the sign of the MV offset added to the starting MV. When the starting MV is a bidirectional prediction MV, and the two MVs point to different sides of the current image (i.e., one reference POC is greater than the current image's POC, and the other reference POC is less than the current image's POC), and the POC difference in list 0 is greater than the POC difference in list 1, the signs in Table 2-3 specify the sign of the MV offset added to the list 0 MV component of the starting MV, and the signs of the list 1 MVs have the opposite value. Otherwise, if the POC difference in List 1 is greater than the POC difference in List 0, then the signs in Table 2-3 specify the signs of the MV offsets of the List 1 MV components added to the starting MV, and the signs of the List 0 MV have the opposite values.

[0079] MVD is scaled based on the difference in POC in each direction. If the difference in POC in the two lists is the same, no scaling is needed. Otherwise, if the difference in POC in list 0 is greater than the difference in POC in list 1, then the MVD of list 1 is scaled by defining the difference in POC in L0 as td and the difference in POC in L1 as tb, as follows. Figure 26 As shown. If the POC difference of L1 is greater than that of L0, then the MVD of list 0 is scaled in the same way. If the initial MV is unidirectionally predicted, then the MVD is added to the available MV.

[0080] Table 2-3 – Signs of MV Offsets Defined by Direction Index

[0081] 2.6. Symmetric MVD Encoding and Decoding In VVC, in addition to the normal one-way and two-way predictive MVD signaling, a symmetric MVD mode for two-way predictive MVD signaling is also applied. In the symmetric MVD mode, the motion information of the MVD of both List 0 and List 1, and List 1, is not transmitted through signals but is derived.

[0082] The decoding process of the symmetric MVD mode is as follows: 1. At the strip level, the variables BiDirPredFlag, RefIdxSymL0, and RefIdxSymL1 are derived as follows: - If mvd_l1_zero_flag is 1, then BiDirPredFlag is set to 0.

[0083] Otherwise, if the most recent reference image in list 0 and the most recent reference image in list 1 form a pair of forward and backward reference images or a pair of backward and forward reference images, then BiDirPredFlag is set to 1, and the reference images in both list 0 and list 1 are short-term reference images. Otherwise, BiDirPredFlag is set to 0.

[0084] 2. At the CU level, if the CU is bidirectional predictive codec and BiDirPredFlag equals 1, the symmetry mode flag, which indicates whether the symmetry mode is used, is explicitly transmitted via signaling.

[0085] When the symmetry mode flag is true, only mvp_l0_flag, mvp_l1_flag, and MVD0 are explicitly transmitted via signals. The reference indices for list 0 and list 1 are each set to a pair of reference images. MVD1 is set to (-MVD0). The final motion vectors are shown in the following formula.

[0086] (2-1) Figure 9 A schematic diagram of the symmetric MVD model is shown. In the encoder, symmetric MVD motion estimation begins with an initial MV evaluation. A set of initial MV candidates includes MVs obtained from a one-way prediction search, MVs obtained from a two-way prediction search, and MVs from an AMVP list. The one with the lowest rate-distortion cost is selected as the initial MV for the symmetric MVD motion search.

[0087] 2.7. Bidirectional Optical Flow (BDOF) The Bidirectional Optical Flow (BDOF) tool is included in VVC. BDOF (formerly known as BIO) was included in JEM. Compared to the JEM version, the BDOF in VVC is a simpler version that requires far less computation, especially in terms of the number of multiplications and the size of the multipliers.

[0088] BDOF is used to refine the bidirectional prediction signal of the CU at the 4x4 sub-block level. BDOF is applied to the CU if all of the following conditions are met: - CU is encoded and decoded using a "true" bidirectional prediction mode, that is, one of the two reference images is displayed before the current image in the order of display, and the other is displayed after the current image in the order of display.

[0089] - The distances (i.e., the difference in point of view) from the two reference images to the current image are the same.

[0090] - Both reference images are short-term reference images.

[0091] - CU is not encoded or decoded using affine mode or SbTMVP Merge mode.

[0092] - The CU has more than 64 luminance samples.

[0093] - Both the CU height and CU width are greater than or equal to 8 luminance samples.

[0094] - The BCW weight index indicates equal weights.

[0095] - WP is not enabled for the current CU.

[0096] - CIIP mode is not used for the current CU.

[0097] BDOF is applied only to the luminance component. As the name suggests, the BDOF mode is based on the concept of optical flow, which assumes that the motion of the object is smooth. For each 4x4 sub-block, motion refinement is calculated by minimizing the difference between the L0 predicted samples and the L1 predicted samples. Motion refinement is then used to adjust the bidirectional prediction sample values ​​in the 4×4 sub-blocks. The following steps are applied during the BDOF process.

[0098] First, the horizontal and vertical gradients of the two predicted signals. It is calculated by directly calculating the difference between two neighboring sample points, that is,

[0099] in It is a list Coordinates of the predicted signal in The sample value at the location, and shift1 is calculated based on the luminance bit depth bitDepth as shift1 = max(6, bitDepth-6).

[0100] Then, the autocorrelation and cross-correlation of the gradients. Calculated as

[0101] in

[0102] in It is a 6x6 window surrounding a 4x4 sub-block, and The values ​​are set to min(1, bitDepth) respectively. 11) and min(4, bitDepth) 8).

[0103] Then the motion is refined. The following is derived using cross-correlation and autocorrelation terms:

[0104] in It is a floor function, and .

[0105] Based on motion refinement and gradients, the following adjustments are calculated for each sample point in the 4x4 sub-block:

[0106] Finally, the BDOF samples of CU are calculated by adjusting the bidirectional prediction samples as follows:

[0107] These values ​​were chosen such that the multiplier in the BDOF process does not exceed 15 bits, and the maximum bit width of the intermediate parameters in the BDOF process is kept within 32 bits.

[0108] To derive the gradient values, the list outside the current CU boundary is used. Some predicted samples in ) It needs to be generated. For example... Figure 10As shown, BDOF in VVC uses an extended row / column around the CU boundary. To control the computational complexity of generating prediction samples outside the boundary, prediction samples in the extended region (white area) are generated by directly taking reference samples at nearby integer positions (using the floor() operation on the coordinates) without interpolation, and a normal 8-tap motion-compensated interpolation filter is used to generate prediction samples inside the CU (gray area). These extended sample values ​​are used only for gradient calculation. For the remaining steps in the BDOF process, if any samples and gradient values ​​outside the CU boundary are needed, they are filled from their nearest neighbors (i.e., repeated).

[0109] When the width and / or height of a CU is greater than 16 luminance samples, it will be divided into sub-blocks with a width and / or height equal to 16 luminance samples, and the sub-block boundaries will be considered as CU boundaries in the BDOF process. The maximum cell size for the BDOF process is limited to 16x16. The BDOF process can be skipped for each sub-block. The BDOF process is not applied to a sub-block when the SAD between the initial L0 and L1 predicted samples is less than a threshold. The threshold is set to (8 * W * (H >> 1), where W indicates the sub-block width and H indicates the sub-block height. To avoid the additional complexity of SAD calculation, the SAD between the initial L0 and L1 predicted samples calculated in the DVMR process is reused here.

[0110] Bidirectional optical flow (BDOF) is disabled if BCW is enabled for the current block, meaning the BCW weight index indicates unequal weights. Similarly, BDOF is disabled if WP is enabled for the current block, meaning luma_weight_lx_flag is 1 for either of the two reference images. BDOF is also disabled when the CU is encoded and decoded in symmetric MVD or CIIP mode.

[0111] 2.8. Inter-frame and Intra-frame Joint Prediction (CIIP) In VVC, when a CU is encoded and decoded in Merge mode, if the CU contains at least 64 luma samples (i.e., the CU width multiplied by the CU height is equal to or greater than 64), and if both the CU width and height are less than 128 luma samples, an additional flag is transmitted via signaling to indicate whether Inter / Intra Joint Prediction (CIIP) mode is applied to the current CU. As the name suggests, CIIP prediction combines inter-frame prediction signals with intra-frame prediction signals. The inter-frame prediction signal in CIIP mode... The inter-frame prediction process is derived using the same procedure as the regular Merge mode; and the intra-frame prediction signal... The conventional intra-frame prediction process utilizing a planar pattern is derived. Then, a weighted average is used to combine the intra-frame and inter-frame prediction signals, where the weight values ​​are based on the top neighbor block and the left neighbor block (e.g., ...). Figure 11 The encoding / decoding mode (as shown) is calculated as follows: - If the top neighboring block is available and is intra-coded, set isIntraTop to 1; otherwise, set isIntraTop to 0. - If the left neighboring block is available and is intra-coded, set isIntraLeft to 1; otherwise, set isIntraLeft to 0. - If (isIntraLeft + isIntraTop) equals 2, then wt is set to 3; - Otherwise, if (isIntraLeft + isIntraTop) equals 1, then wt is set to 2; - Otherwise, set wt to 1.

[0112] The CIIP predictions are formed as follows:

[0113] 2.9. Affine Motion Compensation Prediction In HEVC, only the translational motion model is applied to motion compensation prediction (MCP). In the real world, there are many types of motion, such as zooming in / out, rotation, perspective motion, and other irregular motions. In VVC, block-based affine transformation motion compensation prediction is applied. As shown in Figure 12a (showing a 4-parameter affine model) and Figure 12b (showing a 6-parameter affine model), the affine motion field of a block is described by motion information from motion vectors with two control points (4 parameters) or three control points (6 parameters).

[0114] For a 4-parameter affine motion model, the location of the sample point in the block ( x, y The motion vector at point () is derived as: (2-9) For a 6-parameter affine motion model, the location of the sample points in the block ( x, y The motion vector at point () is derived as: (2-10) in( mv 0x , mv 0y ) is the motion vector of the upper left control point, ( mv 1x , mv 1y) is the motion vector of the upper right control point, and ( mv 2x , mv 2y ) is the motion vector of the lower left control point.

[0115] To simplify motion compensation prediction, block-based affine transformation prediction is applied. To derive the motion vector for each 4x4 luma sub-block, the motion vector of the center sample point of each sub-block is calculated according to the above equation (e.g., ...). Figure 13 (As shown), and rounded to 1 / 16 fractional precision. Then a motion-compensated interpolation filter is applied to generate a prediction for each sub-block with a derived motion vector. The sub-block size for the chroma component is also set to 4x4. The MV of the 4x4 chroma sub-block is calculated as the average of the MVs of the four corresponding 4x4 luma sub-blocks.

[0116] Similar to translational motion inter-frame prediction, there are two affine motion inter-frame prediction modes: affine Merge mode and affine AMVP mode.

[0117] 2.9.1. Affine Merge Prediction The AF_MERGE mode can be applied to CUs with a width and height greater than or equal to 8. In this mode, the CPVM of the current CU is generated based on the motion information of spatially neighboring CUs. There can be up to five CPVM candidates, and the one to be used for the current CU is indicated by a signal transmission index. The following three types of CPVM candidates are used to form the affine merge candidate list: – Inherited affine Merge candidates inferred from the CPMV of neighboring CUs; – A constructive affine Merge candidate CPMVP derived using translational MV of neighboring CUs.

[0118] – Zero MV.

[0119] In VVC, there are at most two inherited affine candidates, which are derived from the affine motion model of neighboring blocks: one from the left neighboring CU and one from the upper neighboring CU. Candidate blocks are as follows: Figure 14 As shown. For the left-hand prediction, the scan order is A0->A1, and for the top-hand prediction, the scan order is B0->B1->B2. Only the first inherited candidate from each side is selected. No deduplication check is performed between candidates from two inherited sides. When a neighboring affine CU is identified, its control point motion vector is used to derive the CPMVP candidate in the affine Merge list of the current CU. As shown, if the neighboring lower-left block A is encoded and decoded in affine mode, the motion vectors of the upper-left, upper-right, and lower-left corners of the CU containing block A are... Obtained. When block A is encoded and decoded using a 4-parameter affine model, the two CPMVs of the current CU are based on... Computed. When block A is encoded and decoded using a 6-parameter affine model, the three CPMVs of the current CU are calculated according to... Calculated. Figure 15 The inheritance of control point motion vectors is shown.

[0120] The constructed affine candidate refers to the candidate built by combining the translational motion information of the neighbors of each control point. The motion information for the control points is derived from... Figure 16 The spatial and temporal nearest neighbors are shown in the derivation. CPMV k (k=1, 2, 3, 4) represents the k-th control point. For CPMV1, check the B2->B3->A2 block and use the MV of the first available block. For CPMV2, check the B1->B0 block, and for CPMV3, check the A1->A0 block. For TMVP, if available, it is used as CPMV4.

[0121] After obtaining the motion signatures (MVs) of the four control points, the affine Merge candidate is constructed based on this motion information. The following combinations of control point MVs are used for sequential construction: {CPMV1, CPMV2, CPMV3}, {CPMV1, CPMV2, CPMV4}, {CPMV1, CPMV3, CPMV4}, {CPMV2, CPMV3, CPMV4}, { CPMV1, CPMV2}, { CPMV1, CPMV3}.

[0122] Combining three CPMVs constructs a 6-parameter affine merge candidate, and combining two CPMVs constructs a 4-parameter affine merge candidate. To avoid motion scaling, combinations of control point MVs are discarded if the reference indices of the control points are different.

[0123] After the inherited affine Merge candidate and the constructed affine Merge candidate are checked, if the list is still not full, zero MV is inserted at the end of the list.

[0124] 2.9.2. Affine AMVP Prediction The affine AMVP mode can be applied to CUs with a width and height greater than or equal to 16. A CU-level affine flag is signaled in the bitstream to indicate whether the affine AMVP mode is used; another flag is signaled to indicate whether it is a 4-parameter affine or a 6-parameter affine. In this mode, the difference between the current CU's CPVM and its predicted CPMVP is signaled in the bitstream. The affine AMVP candidate list is of size 2 and is generated by sequentially using the following four types of CPVM candidates: – Inherited affine AMVP candidates inferred from the CPMV of neighboring CUs.

[0125] – A constructive affine AMVP candidate CPMVP derived using the translational MV of neighboring CUs.

[0126] – Translation MV from the neighboring CU.

[0127] – Zero MV.

[0128] The checking order for inherited affine AMVP candidates is the same as that for inherited affine Merge candidates. The only difference is that, for AVMP candidates, only affine CUs with the same reference picture as those in the current block are considered. No deduplication process is applied when inserting inherited affine motion predictions into the candidate list.

[0129] The constructed AMVP candidate is from Figure 16 The fixed spatial nearest neighbor derivation is shown. The same inspection order as in the affine Merge candidate construction is used. Additionally, the reference picture index of neighboring blocks is checked. The first block in the inspection order that has been inter-frame encoded and decoded and has the same reference picture as in the current CU is used. There is only one. Encoded and decoded in the current CU using a 4-parameter affine mode, and... mv 0 and mv If all three CPMVs are available, they are added to the affine AMVP list as candidates. If the current CU is encoded / decoded in a 6-parameter affine mode and all three CPMVs are available, they are added to the affine AMVP list as candidates. Otherwise, the constructed AMVP candidates are set to unavailable.

[0130] If, after checking the inherited affine AMVP candidates and the constructed AMVP candidates, the affine AMVP list still has fewer than 2 candidates, then mv 0、 mv 1 and mv 2 will be added sequentially as the translation MV of all control points MV of the current CU when available. Finally, if the affine AMVP list is still not full, zero MV is used to fill the affine AMVP list.

[0131] 2.9.3. Affine Motion Information Storage In VVC, the CPMV of an affine CU is stored in a separate cache. The stored CPMV is used only to generate inherited CPMVPs in the affine Merge mode and affine AMVP mode for the most recently encoded / decoded CU. Subblock MVs derived from the CPMV are used for motion compensation, MV derivation of the Merge / AMVP list for translation MVs, and deblocking.

[0132] To avoid caching image rows for additional CPMVs, affine motion data inheritance from CUs of the upper CTU is handled differently from inheritance from regular neighboring CUs. If a candidate CU for affine motion data inheritance is in the upper CTU row, the lower left and lower right sub-block MVs, instead of CPMVs, in the row cache are used for affine MVP derivation. Thus, CPMVs are only stored in the local cache. If the candidate CU is a 6-parameter affine codec, the affine model is downgraded to a 4-parameter model. Figure 17 As shown, along the top CTU boundary, the motion vectors of the lower left and lower right sub-blocks of the CU are used for the affine inheritance of the CU in the bottom CTU.

[0133] 2.9.4. Refinement of Optical Flow Prediction for Affine Modes Compared to pixel-based motion compensation, sub-block-based affine motion compensation saves memory access bandwidth and reduces computational complexity, at the cost of reduced prediction accuracy. To achieve finer-grained motion compensation, Prediction Refinement (PROF) using optical flow is used to refine sub-block-based affine motion compensation predictions without increasing memory access bandwidth for motion compensation. In VVC, after sub-block-based affine motion compensation is performed, the luminance prediction samples are refined by adding the difference derived from the optical flow equation. PROF is described in the following four steps: Step 1) Sub-block-based affine motion compensation is performed to generate sub-block predictions. .

[0134] Step 2) Calculate the spatial gradient of the sub-block prediction at each sample location using a 3-tap filter [-1, 0, 1]. The gradient calculation is exactly the same as the gradient calculation in BDOF.

[0135] (2-11) (2-12) This is used to control the precision of the gradient. For gradient computation, the sub-block (i.e., 4x4) prediction is expanded by one sample on each side. To avoid additional memory bandwidth and additional interpolation computations, those expanded samples on the expanded boundaries are copied from the nearest integer pixel position in the reference image.

[0136] Step 3) Brightness prediction refinement is calculated using the following optical flow equation.

[0137] (2-13) in It refers to the location of the sample points. The calculated sample MV (by (representation) and sample points The difference between the MVs of the sub-blocks of the same sub-block, such as Figure 18 As shown. It is quantized in units of 1 / 32 brightness sample precision.

[0138] Since the affine model parameters and the sample point positions relative to the sub-block center do not change from one sub-block to another, therefore It can be computed for the first sub-block and reused for other sub-blocks in the same CU. This allows... From the sample point location To the center of the sub-block Horizontal and vertical offsets It can be derived from the following equation: (2-14) (2-15) To maintain accuracy, the center of the sub-block Calculated as ( ( W SB 1) / 2, (H) SB 1) / 2), where W SB and H SB These are the width and height of the sub-block.

[0139] For a 4-parameter affine model (2-16) For a 6-parameter affine model (2-17) in These are the motion vectors of the top left, top right, and bottom left control points. These are the width and height of the CU.

[0140] Step 4) Finally, refine the brightness prediction. Added to sub-block prediction Final prediction I’ The following formula is generated.

[0141] (2-18) For affine codecs, PROF is not applied in two cases: 1) all control points MV are the same, which indicates that the CU only has translational motion; 2) the affine motion parameters are greater than the specified limits, because the sub-block-based affine MC is downgraded to the CU-based MC to avoid large memory access bandwidth requirements.

[0142] Fast encoding / decoding methods are applied to reduce the encoding / decoding complexity of affine motion estimation using PROF. PROF is not applied in the affine motion estimation stage in the following two cases: a) if the CU is not the root block and its parent block does not choose an affine mode as its optimal mode, then PROF is not applied because the probability of the current CU choosing an affine mode as its optimal mode is low; b) if the magnitudes of all four affine parameters (C, D, E, F) are less than a predefined threshold, and the current image is not a low-latency image, then PROF is not applied because the improvement introduced by PROF is small in this case. Thus, affine motion estimation using PROF can be accelerated.

[0143] 2.10. Sub-block-based temporal motion vector prediction (SbTMVP) VVC supports a sub-block-based temporal motion vector prediction (SbTMVP) method. Similar to temporal motion vector prediction (TMVP) in HEVC, SbTMVP uses the motion field in the co-image to improve motion vector prediction and merge patterns for the current CU (Cubic Component) in the current image. The same co-image used by TMVP is used for SbTVMP. SbTMVP differs from TMVP in two main aspects: – TMVP predicts motion at the CU level, but SbTMVP predicts motion at the sub-CU level; – TMVP obtains temporal motion vectors from co-op blocks in the co-op image (the co-op block is the lower right or center block relative to the current CU), and SbTMVP applies motion shift before obtaining temporal motion information from the co-op image, where the motion shift is obtained from the motion vector of one of the spatial neighboring blocks from the current CU.

[0144] The SbTVMP process is as follows: Figure 19A and Figure 19B As shown. SbTMVP predicts the motion vectors of sub-CUs within the current CU in two steps. In the first step, it checks... Figure 19A The spatial nearest neighbor A1 in the image is selected. If A1 has a motion vector that uses a co-located image as its reference image, then that motion vector is chosen as the motion shift to be applied. If no such motion is identified, the motion shift is set to (0, 0).

[0145] In the second step, the motion shift identified in step 1 is applied (i.e., added to the coordinates of the current block) to the position of the current block. Figure 19B The corresponding image shown obtains motion information (motion vectors and reference indices) at the sub-CU level. Figure 19B The example assumes that motion shift is set as the motion of block A1. Then, for each sub-CU, the motion information of its corresponding block (the smallest motion grid covering the center sample) in the co-location image is used to derive the motion information for the sub-CU. After the motion information of the co-location sub-CU is identified, it is converted into the motion vector and reference index of the current sub-CU in a manner similar to the TMVP process of HEVC, where temporal motion scaling is applied to align the reference image of the temporal motion vector with the reference image of the current CU.

[0146] Figure 19B The paper demonstrates how to derive the motion field of a sub-CU by applying motion shifts from spatial neighbors and scaling motion information from the corresponding co-located sub-CU.

[0147] In VVC, a sub-block-based Merge list containing a combination of SbTVMP candidates and affine Merge candidates is used for signaling in sub-block-based Merge mode. SbTVMP mode is enabled / disabled via the Sequence Parameter Set (SPS) flag. If SbTVMP mode is enabled, the SbTVMP prediction is added as the first entry in the sub-block-based Merge candidate list, followed by the affine Merge candidate. The size of the sub-block-based Merge list is transmitted via signaling in the SPS, and the maximum allowed size of the sub-block-based Merge list in VVC is 5.

[0148] The sub-CU size used in SbTMVP is fixed at 8x8, and like the affine Merge pattern, the SbTMVP pattern is only applicable to CUs with a width and height greater than or equal to 8.

[0149] The encoding and decoding logic of the additional SbTMVP Merge candidate is the same as that of other Merge candidates. That is, for each CU in the P-strip or B-strip, the additional RD check is performed to determine whether to use the SbTMVP candidate.

[0150] 2.11. Adaptive Motion Vector Resolution (AMVR) In HEVC, when `use_integer_mv_flag` in the strip header is equal to 0, the motion vector difference (MVD) (between the CU's motion vector and the predicted motion vector) is transmitted through the signal in units of quarter-luminance samples. In VVC, a CU-level adaptive motion vector resolution (AMVR) scheme is introduced. AMVR allows the CU's MVD to be encoded and decoded with different precisions. Depending on the current CU's mode (normal AMVP mode or affine AVMP mode), the current CU's MVD can be adaptively selected as follows: - Normal AMVP mode: quarter brightness sample, half brightness sample, integer brightness sample or four brightness sample.

[0151] - Affine AMVP mode: quarter luminance sample, integer luminance sample, or 1 / 16 luminance sample.

[0152] If the current CU has at least one non-zero MVD component, the MVD resolution indication at the CU level is conditionally transmitted via signal transmission. If all MVD components (i.e., both the horizontal and vertical MVD for reference lists L0 and L1) are zero, the quarter-spot luminance sample MVD resolution is presumed.

[0153] For a CU with at least one non-zero MVD component, a first flag is signaled to indicate whether quarter-luminance sample MVD precision is used for the CU. If the first flag is 0, no further signaling is required, and quarter-luminance sample MVD precision is used for the current CU. Otherwise, a second flag is signaled to indicate that half-luminance sample or other MVD precision (integer or quad-luminance sample) is used for the normal AMVP CU. In the case of half-luminance sample, a 6-tap interpolation filter is used instead of the default 8-tap interpolation filter for the half-luminance sample position. Otherwise, a third flag is signaled to indicate whether integer luminance sample MVD precision or quad-luminance sample MVD precision is used for the normal AMVP CU. In the case of an affine AMVP CU, the second flag is used to indicate whether integer luminance sample MVD precision or 1 / 16 luminance sample MVD precision is used. To ensure that the reconstructed MV has the expected precision (quarter-luminance sample, half-luminance sample, integer luminance sample, or quad-luminance sample), the motion vector prediction value for the CU is rounded to the same precision as the MVD before being added to the MVD. The motion vector predictions are rounded to zero (i.e., negative motion vector predictions are rounded to positive infinity, and positive motion vector predictions are rounded to negative infinity).

[0154] The encoder uses RD checksums to determine the motion vector resolution for the current CU. To avoid always performing four CU-level RD checks for each MVD resolution, in VTM 11, RD checks for MVD accuracy other than quarter-luminance samples are only conditionally invoked. For normal AVMP mode, the RD costs for quarter-luminance sample MVD accuracy and integer luminance sample MVD accuracy are first calculated. Then, the RD costs for integer luminance sample MVD accuracy are compared with the RD costs for quarter-luminance sample MVD accuracy to determine if it is necessary to further check the RD costs for four-luminance sample MVD accuracy. When the RD cost for quarter-luminance sample MVD accuracy is significantly less than the RD cost for integer luminance sample MVD accuracy, the RD check for four-luminance sample MVD accuracy is skipped. Then, if the RD cost for integer luminance sample MVD accuracy is significantly greater than the best RD cost of the previously tested MVD accuracy, the check for half-luminance sample MVD accuracy is skipped. For affine AMVP mode, if an affine inter-frame mode is not selected after checking the rate-distortion cost of affine Merge / Skip mode, Merge / Skip mode, quarter-lumen sample MVD precision normal AMVP mode, and quarter-lumen sample MVD precision affine AMVP mode, then 1 / 16-lumen sample MVD precision and 1-pixel MVD precision affine inter-frame modes are not checked. Furthermore, in 1 / 16-lumen sample and quarter-lumen sample MVD precision affine inter-frame modes, the affine parameters obtained in the quarter-lumen sample MVD precision affine inter-frame mode are used as the starting search point.

[0155] 2.12. Using CU-level weighted bidirectional forecasting (BCW) In HEVC, the bidirectional prediction signal is generated by averaging two prediction signals obtained from two different reference images and / or using two different motion vectors. In VVC, the bidirectional prediction mode extends beyond simple averaging to allow for a weighted average of the two prediction signals.

[0156]

[0157] Five weights are allowed in the weighted average two-way forecast. For each bidirectionally predicted CU, the weights w are determined in one of two ways: 1) for non-merge CUs, the weight index is transmitted via signal after the motion vector difference; 2) for merge CUs, the weight index is inferred from neighboring blocks based on the merge candidate index. BCW is applied only to CUs with 256 or more luma samples (i.e., CU width multiplied by CU height is greater than or equal to 256). For low-latency images, all 5 weights are used. For non-low-latency images, only 3 weights are used (w∈{3,4,5}).

[0158] - At the encoder, fast search algorithms are applied to find the weight indices without significantly increasing encoder complexity. These algorithms are summarized below. For further details, readers can refer to the VTM software and documentation JVET-L0646. When combined with AMVR, if the current image is a low-latency image, unequal weights are conditionally checked only for 1-pixel and 4-pixel motion vector precision.

[0159] - When combined with affine mode, affine ME will be performed for unequal weights if and only if the affine mode is selected as the current best mode.

[0160] - When the two reference images in bidirectional prediction are the same, unequal weights are checked only under certain conditions.

[0161] - Based on the POC distance between the current image and its reference image, the encoding / decoding QP, and the temporal level, unequal weights are not searched when certain conditions are met.

[0162] The BCW weight index is encoded using a context-coded bit followed by a bypass-coded bit. The first context-coded bit indicates whether equal weights are used; if unequal weights are used, additional bits are transmitted via bypass encoding to indicate which unequal weights are used.

[0163] Weighted Prediction (WP) is a codec tool supported by the H.264 / AVC and HEVC standards for efficiently encoding and decoding video content with fade-in and fade-out effects. Support for WP has also been added to the VVC standard. WP allows weighting parameters (weights and offsets) to be signal-transmitted for each reference picture in each of the reference picture lists L0 and L1. Then, during motion compensation, the corresponding weights and offsets of the reference picture(s) are applied. WP and BCW are designed for different types of video content. To avoid the interaction between WP and BCW that would complicate the design of the VVC decoder, if the CU uses WP, the BCW weight index is not signal-transmitted, and w is presumed to be 4 (i.e., equal weights are applied). For Merge CUs, the weight index is presumed from neighboring blocks based on the Merge candidate index. This can be applied to both normal Merge patterns and inherited affine Merge patterns. For constructed affine Merge patterns, affine motion information is constructed based on the motion information of up to 3 blocks. The BCW index of the CU using the constructed affine Merge pattern is simply set to be equal to the BCW index of the first control point MV.

[0164] In VVC, CIIP and BCW cannot be jointly applied to a CU. When a CU is encoded or decoded in CIIP mode, the BCW index of the current CU is set to 2, for example, with equal weights.

[0165] 2.13. Local Illumination Compensation (LIC) Local Illumination Compensation (LIC) is an encoding / decoding tool used to address the problem of local illumination variations between the current image and its temporal reference image. LIC is based on a linear model, where a scaling factor and an offset are applied to the reference samples to obtain the predicted samples for the current block. Specifically, LIC can be mathematically modeled by the following equation:

[0166] in In coordinates The prediction signal for the current block at that location; It is composed of motion vectors The reference block it points to; These are the corresponding scaling factors and offsets applied to the reference block. Figure 20 The LIC procedure is shown. Figure 20 In this context, when applying LIC to a block, the Minimum Mean Square Error (LMSE) method is employed to minimize the number of neighboring samples in the current block (i.e., Figure 20 templates in T ) and its corresponding reference sample in the time-domain reference image (i.e., Figure 20 In T0 or T1 The difference between ) is used to derive the LIC parameters (i.e. The value of ). Furthermore, to reduce computational complexity, both the template sample and the reference template sample are downsampled (adaptive downsampling) to derive the LIC parameters; that is, only Figure 20 The shaded samples in the data were used for derivation. .

[0167] To improve encoding and decoding performance, such as Figure 21 As shown, downsampling is not performed on the shorter side.

[0168] 2.14. Decoder-side Motion Vector Refinement (DMVR) To improve the accuracy of motion vector refinement (MV) in the Merge mode, a decoder-side refinement based on bilateral matching (BM) is applied in VVC. In the bidirectional prediction operation, the refined MV is searched around the initial MV in reference image lists L0 and L1. The BM method computes the distortion between two candidate blocks in reference image lists L0 and L1. Figure 22As shown, the SAD between two blocks is calculated based on each MV candidate (e.g., MV0' and MV1') around the initial MV. The MV candidate with the lowest SAD becomes the refined MV and is used to generate the bidirectionally predicted signal.

[0169] In VVC, the application of DMVR is restricted and can only be applied to CUs encoded and decoded in the following modes and features: - CU-level Merge pattern with bidirectional prediction of MV.

[0170] - Relative to the current image, one reference image is from the past and another reference image is from the future.

[0171] - The distances (i.e., the difference in point of view) from the two reference images to the current image are the same.

[0172] - Both reference images are short-term reference images.

[0173] - The CU has more than 64 luminance samples.

[0174] - Both the CU height and CU width are greater than or equal to 8 luminance samples.

[0175] - The BCW weight index indicates equal weights.

[0176] - Disable WP for the current block.

[0177] - CIIP mode is not used in the current block.

[0178] The refined motion vector (MV) derived from the DMVR process is used to generate inter-frame prediction samples and is also used in temporal motion vector prediction for future image encoding and decoding. The original MV is used in the deblocking process and is also used in spatial motion vector prediction for future CU encoding and decoding.

[0179] Additional features of DMVR are mentioned in subsequent sub-entries.

[0180] 2.14.1. Search Scheme In DVMR, the search point revolves around the initial MV, and the MV offset follows the MV difference mirror rule. In other words, any point examined by DMVR, represented by the candidate MV pair (MV0, MV1), obeys the following two equations: (2-20) (2-21) in This represents the refinement offset between the initial MV and the refined MV in one of the reference images. The refinement search range is two integer luminance samples from the initial MV. The search includes an integer sample offset search phase and a fractional sample refinement phase.

[0181] A 25-point full search is applied to the integer sample offset search. The SAD of the initial MV pair is calculated first. If the SAD of the initial MV pair is less than a threshold, the integer sample stage of DMVR is terminated. Otherwise, the SAD of the remaining 24 points is calculated and checked in raster scan order. The point with the smallest SAD is selected as the output of the integer sample offset search stage. To reduce the penalty for uncertainty in DMVR refinement, a bias towards the original MV is proposed during the DMVR process. The SAD value between reference blocks of the initial MV candidate references is reduced by 1 / 4.

[0182] The integer sample search is followed by fractional sample refinement. To save computational complexity, fractional sample refinement is derived using the surface equation of parameter error, rather than through an additional search utilizing SAD comparisons. Fractional sample refinement is conditionally invoked based on the output of the integer sample search phase. Fractional sample refinement is further applied when the integer sample search phase terminates in the first or second iteration with the minimum SAD at the center.

[0183] In subpixel offset estimation based on parametric error surfaces, the cost at the center location and the costs at the four nearest neighbor locations are used to fit a two-dimensional parabolic error surface equation of the following form: (2-22) in( This corresponds to the score position with the minimum cost, and C corresponds to the minimum cost. The above equation is solved by using the costs of the five search points. Calculated as: (2-23) (2-24).

[0184] The value is automatically constrained between -8 and 8 because all values ​​are positive, and the minimum value is... This corresponds to a half-pixel offset with 1 / 16 pixel MV precision in VVC. The calculated score ( It is added to the integer distance thinning MV to obtain subpixel accurate thinning increment MV.

[0185] 2.14.2. Bilinear Interpolation and Sample Filling In VVC, the resolution of the MV is 1 / 16 of a lumen sample. Samples at fractional positions are interpolated using an 8-tap interpolation filter. In DMVR, the search point surrounds the initial fractional pixel MV with an integer sample offset, so samples at those fractional positions need to be interpolated for the DMVR search process. To reduce computational complexity, a bilinear interpolation filter is used to generate fractional samples for the search process in DMVR. Another important effect of using a bilinear filter is that, utilizing a 2-sample search range, DVMR does not access more reference samples compared to the normal motion compensation process. After obtaining the refined MV using the DMVR search process, a normal 8-tap interpolation filter is applied to generate the final prediction. To avoid accessing more reference samples than the normal MC process, samples that are not needed by the interpolation process based on the original MV but are needed by the interpolation process based on the refined MV are filled from those available samples.

[0186] 2.14.3. Maximum DMVR Processing Unit When the width and / or height of a CU is greater than 16 luminance samples, it will be further divided into sub-blocks with a width and / or height equal to 16 luminance samples. The maximum cell size for the DMVR search process is limited to 16x16.

[0187] 2.15. Multi-pass decoder-side motion vector refinement In this document, multi-pass decoder-side motion vector refinement is applied instead of DMVR. In the first pass, bilateral matching (BM) is applied to the codec block. In the second pass, BM is applied to each 16x16 sub-block within the codec block. In the third pass, the motion vectors (MVs) in each 8x8 sub-block are refined by applying bidirectional optical flow (BDOF). The refined MVs are stored for both spatial and temporal motion vector prediction.

[0188] 2.15.1. First pass – Block-based bilateral matching MV refinement In the first pass, the refined MV is derived by applying the BM to the codec block. Similar to decoder-side motion vector refinement (DMVR), the refined MV is searched around the two initial MVs (MV0 and MV1) in the reference picture lists L0 and L1. The refined MVs (MV0_pass1 and MV1_pass1) are derived around the initial MVs based on the minimum bilateral matching cost between the two reference blocks in L0 and L1.

[0189] BM performs a local search to derive the integer sample precision intDeltaMV and the half-pixel sample precision halfDeltaMv. The local search applies a 3x3 square search pattern to iterate through the search range [-sHor, sHor] in the horizontal direction and the search range [-sVer, sVer] in the vertical direction, where the values ​​of sHor and sVer are determined by the block dimension, and the maximum value of sHor and sVer is 8.

[0190] The bilateral matching cost is calculated as: bilCost = mvDistanceCost + sadCost. When the block size cbW * cbH is greater than 64, the MRSAD cost function is applied to remove the DC effect of distortion between reference blocks. The local search of intDeltaMV or halfDeltaMV is terminated when bilCost at the center point of the 3x3 search pattern has the minimum cost. Otherwise, the current minimum cost search point becomes the new center point of the 3x3 search pattern, and the search for the minimum cost continues until it reaches the end of the search range.

[0191] The existing fractional sample refinement is further applied to derive the final deltaMV. The refined MV after the first pass is then derived as: • MV0_pass1 = MV0 + deltaMV, • MV1_pass1 = MV1 – deltaMV.

[0192] 2.15.2. Second pass – Sub-block-based bilateral matching MV refinement In the second pass, the refined MV is derived by applying the BM to 16x16 grid sub-blocks. For each sub-block, the refined MV is searched around the two MVs (MV0_pass1 and MV1_pass1) obtained in the first pass for the reference image lists L0 and L1. The refined MVs (MV0_pass2(sbIdx2) and MV1_pass2(sbIdx2)) are derived based on the minimum bilateral matching cost between the two reference sub-blocks in L0 and L1.

[0193] For each sub-block, BM performs a full search to derive the integer sample precision intDeltaMV. The full search has a search range [-sHor, sHor] in the horizontal direction and a search range [-sVer, sVer] in the vertical direction, where the values ​​of sHor and sVer are determined by the block dimension, and the maximum value of sHor and sVer is 8.

[0194] The bilateral matching cost is calculated by applying a cost factor to the SATD cost between the two reference subblocks, as follows: bilCost = satdCost * costFactor. The search region (2*sHor + 1) * (2*sVer + 1) is divided into... Figure 23 The diagram shows a maximum of five diamond-shaped search regions. Each search region is assigned a costFactor, determined by the distance (intDeltaMV) between each search point and the starting MV, and each diamond region is processed sequentially starting from the center of the search region. Within each region, search points are processed in raster scan order from the top left corner to the bottom right corner of the region. A full integer-pixel search terminates when the minimum bilCost within the current search region is less than a threshold (equal to sbW * sbH); otherwise, the full integer-pixel search continues to the next search region until all search points have been checked.

[0195] BM performs a local search to derive the half-sample precision halfDeltaMv. The search pattern and cost function are the same as defined in 2.9.1.

[0196] The existing VVC DMVR fractional sample refinement is further applied to derive the final deltaMV(sbIdx2). The refined MV at the second pass is then derived as: • MV0_pass2(sbIdx2) = MV0_pass1 + deltaMV(sbIdx2), • MV1_pass2(sbIdx2) = MV1_pass1 – deltaMV(sbIdx2).

[0197] 2.15.3. Third pass – Sub-block based bidirectional optical flow MV refinement In the third pass, the refined MV is derived by applying BDOF to the 8x8 grid sub-blocks. For each 8x8 sub-block, BDOF refinement is applied to derive scaled Vx and Vy, without clipping from the refined MV of the parent block in the second pass. The derived bioMv(Vx, Vy) is rounded to 1 / 16 sample precision and clipped between -32 and 32.

[0198] The refined MVs (MV0_pass3(sbIdx3) and MV1_pass3(sbIdx3)) at the third pass are derived as follows: MV0_pass3(sbIdx3) = MV0_pass2(sbIdx2) + bioMv, •MV1_pass3(sbIdx3) = MV0_pass2(sbIdx2) – bioMv.

[0199] 2.16. Sample-based BDOF In sample-based BDOF, motion refinement is not based on block derivation (Vx, Vy), but is performed on a per-sample basis.

[0200] The encoding / decoding block is divided into 8x8 sub-blocks. For each sub-block, whether to apply BDOF is determined by checking the SAD (Solution-Adjustment) between two reference sub-blocks and a threshold. If BDOF is applied to the sub-block, a sliding 5x5 window is used for each sample in the sub-block, and the existing BDOF process is applied to derive Vx and Vy for each sliding window. The derived motion refinement (Vx, Vy) is applied to adjust the bidirectional prediction sample values ​​for the center sample of the window.

[0201] 2.17. Extended Merge Forecast In VVC, the Merge candidate list is constructed by including the following five types of candidates in sequence: (1) Airspace MVP from the airspace adjacent to the CU.

[0202] (2) Temporal MVP from the same CU.

[0203] (3) History-based MVP from FIFO table.

[0204] (4) Pair average MVP.

[0205] (5) Zero MV.

[0206] The size of the Merge list is transmitted via signaling in the sequence parameter set header, and the maximum allowed size of the Merge list is 6. For each CU encoding / decoding in Merge mode, the index of the best Merge candidate is encoded using rounding unary binarization (TU). The first bit of the Merge index is encoded / decoded using the context, and bypass encoding / decoding is used for the remaining bits.

[0207] This section provides the derivation process for various Merge candidates. Similar to HEVC, VVC also supports parallel derivation of the Merge candidate list for all CUs within a region of a specific size.

[0208] 2.17.1. Derivation of Airspace Candidates The derivation of spatial merge candidates in VVC is the same as that in HEVC, except that the positions of the first two merge candidates are swapped. Figure 24At most four merged candidates are selected from the candidates at the indicated positions. The derivation order is B0, A0, B1, A1, and B2. Position B2 is considered only if one or more CUs at positions B0, A0, B1, and A1 are unavailable (e.g., because it belongs to another stripe or slice) or if it is intra-frame encoded / decoded. After adding the candidate at position A1, a redundancy check is performed on the addition of the remaining candidates. This redundancy check ensures that candidates with the same motion information are excluded from the list, thereby improving encoding / decoding efficiency. To reduce computational complexity, not all possible candidate pairs are considered in the mentioned redundancy check. Instead, only... Figure 25 The system uses arrow links to select pairs, and only adds candidates to the list if the corresponding candidates used for redundancy checks do not have the same motion information.

[0209] 2.17.2. Derivation of Time-Domain Candidates In this step, only one candidate is added to the list. Specifically, in the derivation of this temporal merge candidate, the scaled motion vector is derived based on the co-located CU belonging to the co-located reference image. The list of reference images to be used for the derivation of the co-located CU is explicitly transmitted via signal transmission in the strip header. Figure 26 As shown by the dashed lines, the scaled motion vectors for the temporal merge candidates are obtained by scaling the motion vectors from the co-located CUs using the POC distances tb and td, where tb is defined as the POC difference between the current image and the reference image, and td is defined as the POC difference between the co-located reference image and the co-located image. The reference image index for the temporal merge candidates is set to 0.

[0210] like Figure 27 As shown, the position for the temporal candidate is selected between candidate C0 and C1. If the CU at position C0 is unavailable, intra-frame encoded, or outside the current line of the CTU, position C1 is used. Otherwise, position C0 is used for the derivation of the temporal merge candidate.

[0211] 2.17.3. Historical Merge Candidate Derivation Historically based MVP (HMVP) merge candidates are added to the merge list, following the spatial MVP and TMVP. In this method, motion information from previously encoded / decoded blocks is stored in a table and used as the MVP for the current CU. The table with multiple HMVP candidates is maintained during the encoding / decoding process. The table is reset (cleared) when a new CTU row is encountered. Whenever a non-sub-block inter-frame encoding / decoding CU is present, the associated motion information is added to the last entry of the table as a new HMVP candidate.

[0212] The HMVP table size S is set to 6, indicating that a maximum of 6 history-based MVP (HMVP) candidates can be added to the table. When a new motion candidate is inserted into the table, a constrained First-In-First-Out (FIFO) rule is used, where a redundancy check is first applied to find if a duplicate HMVP already exists in the table. If found, the duplicate HMVP is removed from the table, and all subsequent HMVP candidates are shifted forward, with the duplicate HMVP inserted as the last entry in the table.

[0213] HMVP candidates can be used in the Merge candidate list construction process. The latest HMVP candidates in the table are checked sequentially and inserted into the candidate list after the TMVP candidates. Redundancy checks are applied to HMVP candidates and spatial or temporal Merge candidates.

[0214] To reduce the number of redundant check operations, the following simplifications are introduced: The number of HMPV candidates used in the Merge list generation is set to (N<= 4) ? M: (8 N), where N indicates the number of existing candidates in the Merge list, and M indicates the number of available HMVP candidates in the table.

[0215] Once the total number of available Merge candidates reaches the maximum allowed Merge candidates minus 1, the process of building the Merge candidate list from the HMVP is terminated.

[0216] 2.17.4. Derivation of Pairwise Average Merge Candidates Pairwise averaging candidates are generated by averaging predefined candidate pairs from an existing Merge candidate list. These predefined pairs are defined as {(0, 1), (0, 2), (1, 2), (0, 3), (1, 3), (2, 3)}, where the numbers represent the Merge indices in the Merge candidate list. For each reference list, the averaged motion vector is calculated separately. If two motion vectors are available in a list, they are averaged even if they point to different reference images; if only one motion vector is available, that vector is used directly; if no motion vector is available, the list remains invalid.

[0217] If the Merge list is not full after adding pairwise average Merge candidates, a zero MVP will be inserted at the end until the maximum number of Merge candidates is reached.

[0218] 2.17.5. Merge estimation region The Merge Estimation Region (MER) allows for the independent derivation of Merge candidate lists for Cues (CUs) within the same Merge Estimation Region (MER). Candidate blocks located within the same MER as the current CU are not included in the generation of the Merge candidate list for the current CU. Furthermore, the update process for the historical motion vector prediction candidate list is only updated if (xCb + cbWidth) >> Log2ParMrgLevel is greater than xCb >> Log2ParMrgLevel and (yCb + cbHeight) >> Log2ParMrgLevel is greater than (yCb >> Log2ParMrgLevel), where (xCb, yCb) is the top-left brightness sample position of the current CU in the image, and (cbWidth, cbHeight) is the CU size. The MER size is selected on the encoder side and is transmitted via signaling as log2_parallel_merge_level_minus2 in the sequence parameter set.

[0219] 2.18. New Merge Candidates 2.18.1. Derivation of Non-Adjacent Merge Candidates In VVC, Figure 28 The five spatial neighbor blocks and one temporal nearest neighbor shown were used to derive the Merge candidate.

[0220] We propose using the same pattern as in VVC to derive additional Merge candidates from positions not adjacent to the current block. To achieve this, for each search round i, a virtual block is generated based on the current block, as follows: First, the relative position of the virtual block to the current block is calculated using the following formula: Offsetx =-i×gridX, Offsety = -i×gridY Offsetx and Offsety represent the offset of the top-left corner of the virtual block relative to the top-left corner of the current block, and gridX and gridY are the width and height of the search grid.

[0221] Secondly, the width and height of the virtual block are calculated using the following formula: newWidth = i×2×gridX+ currWidthnewHeight = i×2×gridY +currHeight.

[0222] Where currWidth and currHeight are the width and height of the current block. newWidth and newHeight are the width and height of the new virtual block.

[0223] gridX and gridY are currently set to currWidth and currHeight, respectively.

[0224] Figure 29 This illustrates the relationship between the virtual block and the current block.

[0225] After the virtual block is generated, block A i B i C i D i and E i These can be considered VVC spatial neighbor blocks, and their positions are obtained using the same pattern as the pattern in the VVC. Clearly, if the search round i is 0, the virtual block is the current block. In this case, block A... i B i C i D i and E i It is a spatial neighbor block used in VVC Merge mode.

[0226] When constructing the Merge candidate list, deduplication is performed to ensure that each element in the Merge candidate list is unique. The maximum number of search rounds is set to 1, which means that five non-adjacent spatial neighbor blocks are utilized.

[0227] Non-adjacent spatial domain merge candidates are inserted into the merge list after the temporal domain merge candidates in the order B1->A1->C1->D1->E1.

[0228] 2.18.2. STMVP We propose using three spatial merge candidates and one temporal merge candidate to derive the average candidate as the STMVP candidate.

[0229] STMVP is inserted before the Merge candidate in the upper left airspace.

[0230] STMVP candidates were deduplicated along with all previous Merge candidates in the Merge list.

[0231] For airspace candidates, the top three candidates in the current Merge candidate list are used.

[0232] For time-domain candidates, use the same position as the VTM / HEVC co-position.

[0233] For airspace candidates, the first, second, and third candidates inserted into the current Merge candidate list before STMVP are denoted as F, S, and T.

[0234] In TMVP, time-domain candidates with the same position as VTM / HEVC are denoted as Col.

[0235] The motion vector (denoted as mvLX) of the STMVP candidate in the prediction direction X is derived as follows: 1) If the reference indices of the four Merge candidates are all valid and equal to 0 in the prediction direction X (X = 0 or 1), mvLX = (mvLX_F + mvLX_S + mvLX_T + mvLX_Col)>>2 2) If the reference indices of three out of the four merge candidates are valid and equal to 0 in the prediction direction X (X = 0 or 1), mvLX = (mvLX_F × 3 + mvLX_S × 3 + mvLX_Col × 2)>>3 or mvLX = (mvLX_F × 3 + mvLX_T × 3 + mvLX_Col × 2)>>3 or mvLX = (mvLX_S × 3 + mvLX_T × 3 + mvLX_Col × 2)>>3.

[0236] 3) If the reference indices of two of the four merge candidates are valid and equal to 0 in the prediction direction X (X = 0 or 1), mvLX = (mvLX_F + mvLX_Col)>>1 or mvLX = (mvLX_S + mvLX_Col)>>1 or mvLX = (mvLX_T + mvLX_Col)>>1.

[0237] Note: STMVP mode is turned off if time-domain candidates are not available.

[0238] 2.18.3. Merge list size If both non-adjacent Merge candidates and STMVP Merge candidates are considered, the size of the Merge list is signaled in the sequence parameter set header, and the maximum allowed size of the Merge list is 8.

[0239] 2.19. Geometric Partitioning (GPM) In VVC, geometric segmentation modes are supported for inter-frame prediction. Geometric segmentation modes are transmitted via signaling using a CU-level flag as a merge mode, where other merge modes include regular merge mode, MMVD mode, CIIP mode, and sub-block merge mode. This applies to each possible CU size. (in Excluding 8x64 and 64x8, the geometric segmentation mode supports a total of 64 segments.

[0240] When using this mode, the CU is divided into two parts by a straight line of geometric positioning ( Figure 30 The position of the dividing line is mathematically derived from the angle and offset parameters of a specific segment. Each part of the geometric segment in the CU is predicted inter-frame using its own motion; only unidirectional prediction is allowed for each segment, i.e., each part has one motion vector and one reference index. Unidirectional prediction motion constraints are applied to ensure that, as with regular bidirectional prediction, only two motion-compensated predictions are required for each CU. The unidirectional prediction motion for each segment is derived using the process described in 2.19.1.

[0241] If a geometric segmentation pattern is used for the current CU, the geometric segmentation pattern (angle and offset) and two merge indices (one for each segment) are further indicated via signal transmission. The number of maximum GPM candidate sizes is explicitly transmitted in the SPS, and the syntax binarization used for the GPM merge indices is specified. After predicting each part of the geometric segmentation, a blending process with adaptive weights, as described in 2.19.2, is used to adjust the sample values ​​along the geometric segmentation edges. This is the prediction signal for the entire CU, and the transformation and quantization processes are applied to the entire CU as in other prediction patterns. Finally, the motion field of the CU predicted using the geometric segmentation pattern is stored, as described in 2.19.3.

[0242] 2.19.1. Construction of One-Way Prediction Candidate List The unidirectional prediction candidate list is directly derived from the Merge candidate list constructed according to the extended Merge prediction process in 2.17. Let n denote the index of the unidirectional predicted motion in the geometric unidirectional prediction candidate list. The LX motion vector of the nth extended Merge candidate (where X equals the parity of n) is used as the nth unidirectional predicted motion vector for the geometric segmentation pattern. These motion vectors in... Figure 31 The value is marked with "x". If the corresponding LX motion vector of the nth extended Merge candidate does not exist, then the L(1) of the same candidate... The X motion vector is used as a unidirectional predictive motion vector for the geometric segmentation pattern.

[0243] 2.19.2. Blending along geometrically segmented edges After each part of the geometric segmentation using its own motion prediction, blending is applied to the two prediction signals to derive samples around the geometric segmentation edges. The blending weights for each location of the CU are derived based on the distance between the individual location and the segmentation edge.

[0244] Location The distance to the segmentation edge is derived as follows: (2-25) (2-26) (2-27) (2-28) in It is an index for the angle and offset of the geometric segmentation, which depends on the geometric segmentation index transmitted via signal. The sign depends on the angle index. .

[0245] The weights for each part of the geometric segment are derived as follows: (2-29) (2-30) (2-31) partIdx depends on the angle index Weight An example in Figure 32 It is shown in the middle.

[0246] 2.19.3. Motion field storage for geometric segmentation patterns Mv1 from the first part of the geometric segmentation, Mv2 from the second part of the geometric segmentation, and the combination Mv of Mv1 and Mv2 are stored in the motion field of the CU encoded and decoded by the geometric segmentation pattern.

[0247] The type of motion vector stored for each individual location in the sports field is determined as follows: (2-32) Where motionIdx equals It is recalculated from equation (2-18). `partIdx` depends on the angle index. .

[0248] If sType equals 0 or 1, then Mv0 or Mv1 is stored in the corresponding motion field; otherwise, if sType equals 2, then the combination Mv from Mv0 and Mv2 is stored. The combination Mv is generated using the following procedure: 1) If Mv1 and Mv2 come from different lists of reference images (one from L0 and the other from L1), then Mv1 and Mv2 are simply combined to form a bidirectional predicted motion vector.

[0249] Otherwise, if Mv1 and Mv2 come from the same list, only the unidirectional predicted motion Mv2 is stored.

[0250] 2.20. Multiple Hypothesis Prediction In multiple hypothesis prediction (MHP), up to two additional predictions are transmitted over the signal, in addition to inter-frame AMVP mode, regular Merge mode, affine Merge mode, and MMVD mode. The resulting overall prediction signal is iteratively accumulated with each additional prediction signal.

[0251]

[0252] The weighting factors are specified in Table 2-4 below. α : Table 2-4 – Weighting Factors for MHP

[0253] For inter-frame AMVP mode, MHP is applied only if unequal weights are selected in BCW in bidirectional prediction mode.

[0254] Additional assumptions can be either Merge or AMVP mode. In Merge mode, motion information is indicated via the Merge index, and the Merge candidate list is the same as in the geometry segmentation mode. In AMVP mode, the reference index, MVP index, and MVD are transmitted via signals.

[0255] 2.21. Non-adjacent airspace candidates Non-adjacent airspace merge candidates are inserted after the TMVP in the regular merge candidate list. The style of airspace merge candidates is as follows: Figure 33 The distance between non-adjacent spatial domain candidates and the current codec block is shown in the diagram. The distance between the current codec block and the non-adjacent spatial domain candidate is based on the width and height of the current codec block.

[0256] 2.22. Template Matching (TM) Template matching (TM) is a decoder-side MV derivation method used to refine the motion information of the current CU by finding the closest match between a template in the current image (i.e., the top and / or left neighboring blocks of the current CU) and a block in the reference image (i.e., of the same size as the template). For example... Figure 34As shown, within the search range of [-8, +8] pixels, a better MV is searched around the initial motion of the current CU. The template matching previously proposed in JVET-J0021 is adopted with two modifications: the search step size is determined based on the AMVR mode, and in the Merge mode, the TM can be cascaded with the bilateral matching process.

[0257] In AMVP mode, MVP candidates are determined based on template matching error, selecting the one that minimizes the difference between the current block template and the reference block template. TM then performs MV refinement only on that specific MVP candidate. TM refines the MVP candidate using an iterative diamond search, starting with full-pixel MVD precision (or 4 pixels for 4-pixel AMVR mode) within a search range of [-8, +8] pixels. AMVP candidates can be further refined using a cross search with full-pixel MVD precision (or 4 pixels for 4-pixel AMVR mode), followed by half-pixels and quarter-pixels sequentially according to the AMVR mode specified in Table 2-5. This search process ensures that the MVP candidate maintains the same MV precision as indicated by the AMVR mode after the TM process.

[0258] Table 2-5 – Search Styles for AMVR and Search Styles with AMVR Merge Pattern

[0259] In Merge mode, a similar search method is applied to the Merge candidates indicated by the Merge index. As shown in Table 2-5, TM can proceed up to 1 / 8 pixel MVD precision, or skip those precisions beyond half-pixel MVD precision, depending on whether an alternative interpolation filter is used based on the merged motion information (i.e., used when AMVR is in half-pixel mode). Furthermore, when TM mode is enabled, template matching can run as a standalone process or as an additional MV refinement process between block-based and sub-block-based bilateral matching (BM) methods, depending on whether BM can be enabled according to its enable condition check.

[0260] 2.23. Overlapping Block Motion Compensation (OBMC) Overlapping Block Motion Compensation (OBMC) has previously been used in H.263. In JEM, unlike H.263, OBMC can be turned on and off using CU-level syntax. When using OBMC in JEM, it is performed on all motion compensation (MC) block boundaries except for the right and bottom boundaries of the CU. Furthermore, it is applied to both the luma and chroma components. In JEM, MC blocks correspond to codec blocks. When a CU is encoded and decoded in sub-CU modes (including sub-CU merge, affine, and FRUC modes), each sub-block of the CU is an MC block. To handle CU boundaries uniformly, OBMC is performed at the sub-block level for all MC block boundaries, where the sub-block size is set to equal to 4x4, such as... Figure 35 As shown.

[0261] When OBMC is applied to the current sub-block, in addition to the current motion vector, the motion vectors of four connected neighboring sub-blocks (if available and not identical to the current motion vector) are also used to derive prediction blocks for the current sub-block. These multiple prediction blocks based on multiple motion vectors are combined to generate the final prediction signal for the current sub-block.

[0262] The predicted block based on the motion vectors of neighboring sub-blocks is represented as PN, where N represents the index of the neighboring above, below, left, and right sub-blocks, and the predicted block based on the motion vector of the current sub-block is represented as PC. When PN is based on the motion information of neighboring sub-blocks containing the same motion information as the current sub-block, OBMC from PN is not performed. Otherwise, each sample of PN is added to the corresponding sample in PC, i.e., four rows / columns of PN are added to PC. Weighting factors {1 / 4, 1 / 8, 1 / 16, 1 / 32} are used for PN, and weighting factors {3 / 4, 7 / 8, 15 / 16, 31 / 32} are used for PC. An exception is small MC blocks (i.e., when the height or width of the codec block is equal to 4 or the CU is encoded in subCU mode). For small MC blocks, only two rows / columns of PN are added to PC. In this case, weighting factors {1 / 4, 1 / 8} are used for PN, and weighting factors {3 / 4, 7 / 8} are used for PC. For a PN generated based on the motion vectors of vertical (horizontal) neighboring sub-blocks, samples in the same row (column) of the PN are added to the PC with the same weighting factor.

[0263] In JEM, for CUs with a size of 256 lumen samples or less, a CU level flag is transmitted via signaling to indicate whether OBMC is applied to the current CU. For CUs with a size greater than 256 lumen samples or not encoded / decoded in AMVP mode, OBMC is applied by default. At the encoder, when OBMC is applied to the CU, its effect is considered during the motion estimation phase. The predicted signal formed by OBMC using motion information from the top and left neighbor blocks is used to compensate for the top and left boundaries of the original signal of the current CU, and then the normal motion estimation process is applied.

[0264] 2.24. Multiple Transform Selection (MTS) for Core Transformation In addition to DCT-II, which is already used in HEVC, the Multiple Transform Selection (MTS) scheme is also used for residual coding and decoding of both inter-frame and intra-frame codec blocks. It uses multiple transforms selected from DCT8 / DST7. The newly introduced transform matrices are DST-VII and DCT-VIII. Table 2-6 shows the basis functions of the selected DST / DCT.

[0265] Table 2-6 – Transform basis functions for DCT-II / VIII and DSTVII for N-point inputs

[0266] To maintain the orthogonality of the transformation matrices, the transformation matrices are quantized more precisely than those in HEVC. To keep the intermediate values ​​of the transformation coefficients within the 16-bit range, all coefficients must have 10 bits after both the horizontal and vertical transformations.

[0267] To control the MTS scheme, separate enable flags are specified at the SPS level for intra-frame and inter-frame operations. When MTS is enabled in SPS, a CU-level flag is signaled to indicate whether MTS is applied. Here, MTS is applied only to luminance. MTS signaling is skipped when one of the following conditions is met.

[0268] – The position of the last significant coefficient for luminance TB is less than 1 (i.e., DC only).

[0269] – The last significant coefficient of luminance TB is located within the MTS zeroing region.

[0270] If the MTS CU flag is equal to 0, DCT2 is applied in both directions. However, if the MTS CU flag is equal to 1, two additional flags are transmitted via signaling to indicate the transform type for the horizontal and vertical directions, respectively. The transform and signaling mapping table is shown in Table 2-7. A unified transform selection for ISP and implicit MTS is used by removing intra-frame mode and block shape dependencies. If the current block is in ISP mode, or if the current block is an intra-frame block and both intra-frame explicit MTS and inter-frame explicit MTS are enabled, only DST7 is used for both the horizontal and vertical transform kernels. An 8-bit main transform kernel is used when transform matrix precision is involved. Therefore, all transform kernels used in HEVC remain unchanged, including 4-point DCT-2 and DST-7, 8-point, 16-point, and 32-point DCT-2. In addition, other transform kernels (including 64-point DCT-2, 4-point DCT-8, 8-point, 16-point, and 32-point DST-7 and DCT-8) use an 8-bit main transform kernel.

[0271] Table 2-7 – Transformation and signaling mapping table

[0272] To reduce the complexity of large-sized DST-7 and DCT-8 blocks, the high-frequency transform coefficients are zeroed out for DST-7 and DCT-8 blocks with a size (width or height, or both) equal to 32. Only the coefficients in the 16x16 low-frequency region are retained.

[0273] In HEVC, for example, block residuals can be encoded and decoded in transform skip mode. To avoid redundancy in syntax encoding and decoding, the transform skip flag is not signaled when the CU-level MTS_CU_flag is not equal to 0. Note that when LFNST or MIP is activated for the current CU, the implicit MTS transform is set to DCT2. Implicit MTS can also be enabled when MTS is enabled for inter-frame encoding / decoding blocks.

[0274] 2.25. Subblock Transformation (SBT) In VTM, a CU subblock transform is introduced for inter-frame prediction. In this transform mode, only a sub-part of the residual block is encoded / decoded for the CU. When inter-frame prediction of the CU is cu_cbf equal to 1, the signal cu_sbt_flag can be used to indicate whether the entire residual block or a sub-part of the residual block is encoded / decoded. In the former case, the inter-frame MTS information is further parsed to determine the transform type of the CU. In the latter case, a portion of the residual block is encoded / decoded using a presumed adaptive transform, and the other portion of the residual block is zeroed out.

[0275] When SBTs are used in inter-frame encoding / decoding CUs, the SBT type and SBT position information are transmitted via signals in the bitstream. For example... Figure 36 As shown, there are two SBT types and two SBT locations. For SBT-V (or SBT-H), the TU width (or height) can be equal to half the CU width (or height) or 1 / 4 of the CU width (or height), resulting in a 2:2 partition or a 1:3 / 3:1 partition. A 2:2 partition is like a binary tree (BT) partition, while a 1:3 / 3:1 partition is like an asymmetric binary tree (ABT) partition. In an ABT partition, only small regions contain non-zero residuals. If one dimension of the CU is 8 in the luma sample, a 1:3 / 3:1 partition along that dimension is prohibited. There can be a maximum of 8 SBT modes for a CU.

[0276] Position-dependent transform kernel selection is applied to the luma transform blocks in SBT-V and SBT-H (chroma TB always uses DCT-2). Two positions in SBT-H and SBT-V are associated with different kernel transforms. More specifically, the horizontal and vertical transforms for each SBT position are... Figure 36 The transformations are specified in the code. For example, the horizontal and vertical transformations for position 0 of SBT-V are DCT-8 and DST-7, respectively. When one side of the residual TU is greater than 32, the transformations for both dimensions are set to DCT-2. Therefore, the sub-block transformations collectively define the TU slice, cbf, and the horizontal and vertical core transformation types of the residual block.

[0277] SBT is not applied to CUs encoded and decoded in inter-frame and intra-frame combination mode.

[0278] 2.26. Adaptive Merge Candidate Reordering Based on Template Matching To improve encoding and decoding efficiency, after the merge candidate list is constructed, the order of each merge candidate is adjusted according to the template matching cost. The merge candidates are arranged in the list according to their ascending template matching cost. This is done in subgroups.

[0279] Template matching cost is measured by the sum of absolute differences (SAD) between the current CU's neighboring samples and their corresponding reference samples. If the merge candidate includes bidirectional predicted motion information, then... Figure 37 As shown, the corresponding reference sample is the average of the corresponding reference sample in reference list 0 and the corresponding reference sample in reference list 1. If the Merge candidate contains motion information at the sub-CU level, then as follows... Figure 38 As shown, the corresponding reference sample point is composed of the neighboring sample points of the corresponding reference sub-block.

[0280] like Figure 39 As shown, the sorting process is performed in subgroups. The first three merge candidates are sorted together. The last three merge candidates are sorted together.

[0281] The template size (width of the left template or height of the top template) is 1. The subgroup size is 3.

[0282] 2.27. Adaptive Merge Candidate List We can assume there are 8 merge candidates. The first 5 merge candidates are designated as the first subgroup, and the last 3 merge candidates are designated as the second subgroup (i.e., the last subgroup).

[0283] For the encoder, after the Merge candidate list is constructed, such as Figure 40 As shown, some Merge candidates are adaptively reordered in ascending order of Merge candidate cost.

[0284] More specifically, the template matching cost of the Merge candidates in all subgroups except the last subgroup is calculated; then the Merge candidates in their own subgroups except the last subgroup are reordered; finally, the final list of Merge candidates is obtained.

[0285] For the decoder, after the Merge candidate list is constructed, such as Figure 41 As shown, some / no merge candidates are adaptively reordered in ascending order at the merge candidate cost. Figure 41 In this context, the subgroup containing the selected (transmitted via signal) Merge candidate is referred to as the selected subgroup.

[0286] More specifically, if the selected Merge candidate is in the last subgroup, the Merge candidate list construction process is terminated after deriving the selected Merge candidate, no reordering is performed, and the Merge candidate list remains unchanged; otherwise, the process is as follows: After deriving all Merge candidates in the selected subgroup, the Merge candidate list construction process is terminated; the template matching cost for the Merge candidates in the selected subgroup is calculated; the Merge candidates in the selected subgroup are reordered; finally, a new Merge candidate list is obtained.

[0287] For both the encoder and decoder, the template matching cost is derived as a function of T and RT, where T is the set of samples in the template and RT is the set of reference samples for the template.

[0288] When deriving reference samples for the template of the Merge candidate, the motion vector of the Merge candidate is rounded to integer pixel precision.

[0289] The reference samples (RT) for the template used for bidirectional prediction are obtained by using the reference samples of the template in reference list 0 as follows ( ) and reference samples of the template in reference list 1 ( It is derived by weighted averaging.

[0290] (2-33) The weights (8-w) of the reference templates in reference list 0 and the weights (w) of the reference templates in reference list 1 are determined by the BCW indices of the Merge candidates. The BCW indices equal to {0,1,2,3,4} correspond to w equal to {-2,3,4,5,10}, respectively.

[0291] If the Local Illumination Compensation (LIC) flag of the Merge candidate is true, the reference sample points of the template are derived using the LIC method.

[0292] Template matching cost is calculated based on the sum of absolute differences (SAD) between T and RT.

[0293] The template size is 1. This means that the width of the left template and / or the height of the top template is 1.

[0294] If the encoding / decoding mode is MMVD, the Merge candidates used to derive the base Merge candidates are not reordered.

[0295] If the encoding / decoding mode is GPM, the Merge candidates used to derive the one-way prediction candidate list are not reordered.

[0296] 2.28. Geometric prediction model with motion vector difference In Geometric Prediction Mode with Motion Vector Difference (GMVD), each geometric segment in GPM can determine whether GMVD is used. If GMVD is selected for a geometric region, the MV of that region is calculated as the sum of the MV of the merged candidates and the MVD. All other processing remains the same as in GPM.

[0297] Using GMVD, MVD is transmitted as a pair of directions and distances via signals. Nine candidate distances are involved (1 / 4 pixel, 1 / 2 pixel, 1 pixel, 2 pixels, 3 pixels, 4 pixels, 6 pixels, 8 pixels, 16 pixels) and eight candidate directions (four horizontal / vertical directions and four diagonal directions). Additionally, when pic_fpel_mmvd_enabled_flag equals 1, the MVD in GMVD is shifted left by 2, just like in MMVD.

[0298] 2.29. Affine Model Inheritance and Non-Adjacent Affine Modes Based on Historical Parameters History-based Affine Model Inheritance (HAMI) allows affine models to be inherited from previously affine-encoded blocks that may not be adjacent to the current block. Similar to the enhanced regular Merge mode, Non-Adjacent Affine Mode (NA-AFF) is introduced.

[0299] The first history parameter table (HPT) is established. Each entry in the first HPT stores a set of affine parameters: a , b , c and d Each affine parameter is represented by a 16-bit signed integer. Entries in the HPT are categorized by reference list and reference index. Five reference indices are supported for each reference list in the HPT. The HPT category (denoted as HPTCat) is calculated in a formulaic manner as follows: HPTCat (RefList, RefIdx) = 5×RefList + min (RefIdx, 4), RefList and RefIdx represent the list of reference images (0 or 1) and the reference index, respectively. A maximum of 7 entries can be stored for each category, resulting in a total of 70 entries in the HPT. At the beginning of each CTU line, the number of entries for each category is initialized to zero. Decoding involves using the reference list RefList... cur and RefIdx cur After the affine codec (CU), the affine parameters are used to update the category HPTCat(RefList) in a manner similar to HMVP table updates. cur RefIdx cur The entries in.

[0300] Candidates based on historical affine parameters (HAPC) from... Figure 42 The MV of one of the seven neighboring 4x4 blocks, represented as A0, A1, A2, B0, B1, B2, or B3, and a set of affine parameters stored in the corresponding entries in the first HPT are derived. The MV of the neighboring 4x4 blocks is used as the base MV. In a formulaic manner, the current block at position ( x , y The MV at () is calculated as: , in( mv h base , mv v base ) represents the MV of the adjacent 4x4 block, ( x base , y base() indicates the center location of the adjacent 4x4 block. x , y The MV can be the top left, top right, or bottom left corner of the current block to obtain the corner position MV (CPMV) for the current block, or it can be the center of the current block to obtain the regular MV for the current block.

[0301] A second history parameter table (HPT) containing basic MV information was also added. The second HPT contains nine entries, each including the basic MV, reference index, four affine parameters for each reference list, and the base position. An additional Merge HAPC can be generated from the second HPT, which stores the basic MV information and corresponding affine models in the entries. The difference between the first and second HPTs is... Figure 42 It is shown in the middle.

[0302] Furthermore, paired affine merge candidates are generated from two affine merge candidates, either historically derived or not. Paired affine merge candidates are generated by averaging the CPMV of existing affine merge candidates in the list.

[0303] In response to the introduction of the new HAPC, the size of the sub-block-based Merge candidate list was increased from 5 to 15, all of which are involved in the ARMC process.

[0304] In NA-AFF, the style for obtaining the nearest neighbors of non-adjacent spatial domains is as follows: Figure 43A and Figure 43B As shown. Figure 43A Candidates for deriving inheritance are shown, and Figure 43B Candidates for deriving the first type of construction are shown. Similar to existing non-adjacent regular Merge candidates, the distance between non-adjacent spatial neighbors in NA-AFF and the current codec block is also defined based on the width and height of the current CU.

[0305] Figure 43A and Figure 43B Motion information of non-adjacent spatial neighbors in the VVC is used to generate additional inherited and constructed affine Merge / AMVP candidates. Specifically, for inherited candidates, the same derivation process for inherited affine Merge / AMVP candidates in the VVC remains unchanged, except that CPMV inherits from non-adjacent spatial neighbors. Non-adjacent spatial neighbors are checked based on their distance from the current block (i.e., from nearest to farthest). At a specific distance, for the candidate derivation of inheritance, only the first available neighbor (encoded in affine mode) from each side (e.g., left and top) of the current block is included. Figure 43A As shown by the red dashed arrows in the image, the order of checking the nearest neighbors on the left and top is from bottom to top and from right to left, respectively.

[0306] For candidates of the first type of construction, such as Figure 43B As shown, the positions of a non-adjacent spatial neighbor on the left and a non-adjacent spatial neighbor above are first determined independently; then, the position of the upper-left neighbor can be determined accordingly, which can form a rectangular virtual block together with the non-adjacent neighbors on the left and above. Then, as... Figure 44 As shown, motion information from three non-adjacent nodes is used to form a CPMV at the top left (A), top right (B), and bottom left (C) of the virtual block, which is then projected onto the current CU to generate corresponding candidate builds.

[0307] NA-AFF candidates are inserted into the existing affine Merge candidate list and affine AMVP candidate list in the following order: Affine Merge Mode: 1. SbTMVP candidate, if available.

[0308] 2. Inherit from the nearest neighbor.

[0309] 3. Inherited from non-adjacent neighbors.

[0310] 4. Build from neighboring neighbors.

[0311] 5. Affine candidates from the first type of construction that are not adjacent to each other.

[0312] 6. Zero MV.

[0313] Affine AMVP mode: 1. Inherit from the nearest neighbor.

[0314] 2. Build from neighboring neighbors.

[0315] 3. Translation MV from neighboring units.

[0316] 4. Translation MV from temporal nearest neighbor.

[0317] 5. Inherited from non-adjacent neighbors.

[0318] 6. Affine candidates from the first type of construction that are not adjacent to each other.

[0319] 7. Zero MV.

[0320] The size of the affine Merge candidate list has increased from 5 to 15 due to the inclusion of additional candidates generated by NA-AFF. The size of the subgroups for ARMCs for the affine Merge pattern has increased from 3 to 15.

[0321] Figure 43A and Figure 43BThe spatial nearest neighbor used to derive affine Merge / AMVP candidates is shown: Figure 43A Used to derive candidates for inheritance, and Figure 43B Candidates for deriving the first type of construction.

[0322] In NA-AFF: 1. Regions from which non-adjacent neighbors originate are restricted to the current CTU (i.e., there are no additional storage requirements for the row cache).

[0323] 2. The storage granularity for affine motion information (including CPMV and reference index) is reduced from 8x8 to 16x16 (i.e., only affine motion from the top-left 8x8 block is saved). Additionally, the saved CPMV is projected onto each 16x16 block before storage, eliminating the need for position and size information.

[0324] 3. Only the top left and top right CPMVs are stored (i.e., always using the 4-parameter affine model for NA-AFF).

[0325] 2.30. Affine MMVD In affine MMVD, affine Merge candidates (referred to as basic affine Merge candidates) are selected, and the MV of the control points is further refined through the MVD information transmitted via signals.

[0326] The MVD information for the MV of all control points is the same in one prediction direction.

[0327] When the starting MV is a bidirectional prediction MV and the two MVs point to different sides of the current image (i.e., one reference POC is greater than the current image's POC, and the other reference POC is less than the current image's POC), the MV offset of the list 0 MV component added to the starting MV has the opposite value to the MV offset for the list 1 MV; otherwise, when the starting MV is a bidirectional prediction MV and both lists point to the same side of the current image (i.e., both reference POCs are greater than the current image's POC, or both are less than the current image's POC), the MV offset of the list 0 MV component added to the starting MV is the same as the MV offset for the list 1 MV.

[0328] 2.31. Adaptive Decoder-Side Motion Vector Refinement (ADMVR) In ECM-2.0, if the selected merge candidate satisfies the DMVR condition, a multi-pass decoder-side motion vector refinement (DMVR) method is applied in the regular merge mode. In the first pass, bilateral matching (BM) is applied to the codec block. In the second pass, BM is applied to each 16x16 sub-block within the codec block. In the third pass, the motion vectors (MVs) in each 8x8 sub-block are refined by applying bidirectional optical flow (BDOF).

[0329] The adaptive decoder-side motion vector refinement method consists of two new Merge modes, which are introduced to refine the motion vectors only in one direction (L0 or L1) of the bidirectional predictions of Merge candidates that satisfy the DMVR condition. A multi-pass DMVR process is applied to the selected Merge candidates to refine the motion vectors; however, in the first pass (i.e., PU level) of the DMVR, either MVD0 or MVD1 is set to zero.

[0330] Similar to the regular Merge pattern, the Merge candidates for the proposed Merge pattern are derived from spatially adjacent encoded / decoded blocks, TMVPs, non-adjacent blocks, HMVPs, and paired candidates. The difference is that only those satisfying the DMVR conditions are added to the candidate list. Both proposed Merge patterns use the same Merge candidate list (i.e., the ADMVR Merge list), and the encoding / decoding of the Merge index is the same as in the regular Merge pattern.

[0331] 2.32. IBC with Template Matching It is proposed that template matching be used for both the IBC Merge pattern and the IBC AMVP pattern.

[0332] Compared to the list used in the regular IBC Merge mode, the IBC-TM Merge list has been modified so that candidates are selected based on a deduplication method, where the motion distance between candidates is the same as in the regular TM Merge mode. The zero-motion satisfying condition (which is meaningless with respect to intra-frame encoding / decoding) has been replaced with motion vectors to the left (-W, 0), top (0, -H), and top-left (-W, -H) CUs. Then, if necessary, the list is satisfied using the left-hand CU without deduplication.

[0333] In IBC-TM Merge mode, the selected candidate is refined using a template matching method before the RDO or decoding process. IBC-TM Merge mode competes with the regular IBC Merge mode, and the TM-Merge flag is transmitted via signaling.

[0334] In the IBC-TM AMVP mode, up to three candidates are selected from the IBC Merge list. Each of these three candidates is refined using a template matching method and ranked according to the template matching cost it produces. Then, typically only the top two candidates are considered in the motion estimation process.

[0335] Because the IBC motion vector is constrained to integers and in such a way Figure 45 Within the reference area shown, template matching refinement is therefore fairly straightforward for both IBC-TM Merge and AMVP modes. Thus, in IBC-TM Merge mode, all refinements are performed with integer precision, and in IBC-TM AMVP mode, they are performed with either integer precision or 4-pixel precision. In both cases, the refined motion vectors in each refinement step must adhere to the constraints of the reference area.

[0336] 2.33. IBC Merge Mode with Block Vector Difference The IBC Merge pattern with block vector difference is shown below. The distance set is {1 pixel, 2 pixels, 4 pixels, 8 pixels, 12 pixels, 16 pixels, 24 pixels, 32 pixels, 40 pixels, 48 ​​pixels, 56 pixels, 64 pixels, 72 pixels, 80 pixels, 88 pixels, 96 pixels, 104 pixels, 112 pixels, 120 pixels, 128 pixels}, and the BVD directions are two horizontal directions and two vertical directions.

[0337] The base candidates are selected from the top five candidates in the reordered IBC Merge list. And based on the SAD cost between the template (the row above and column to the left of the current block) and its reference for each base candidate, all possible MBVD refinement positions (20x4) are reordered. Finally, the top 8 refinement positions with the lowest template SAD cost are reserved as available positions for MBVD index encoding and decoding.

[0338] 2.34. Reconstructing the Reordered IBC (RR-IBC) Screen content codecs such as Intra-Block Copy (IBC) generate predictive blocks by directly copying previously encoded reference regions from the same frame. Symmetry is frequently observed in video content, particularly in text character regions and computer-generated graphics within sequences of screen content, such as... Figure 46 As shown. Therefore, specific screen content encoding / decoding tools that take into account symmetry will effectively compress this type of video content.

[0339] For video encoding and decoding of screen content, a Reconstruction Reordering IBC (RR-IBC) mode is proposed. When applied, samples in the reconstructed block are flipped according to the flip type of the current block. On the encoder side, the original block is flipped before motion search and residual calculation, while the predicted block is derived without flipping. On the decoder side, the reconstructed block is flipped back to recover the original block.

[0340] For blocks encoded and decoded using RR-IBC, two flipping methods are supported: horizontal flipping and vertical flipping. First, for blocks encoded and decoded using IBC AMVP, a syntax flag is signaled to indicate whether the reconstruction has been flipped. If it has been flipped, another flag is further signaled to specify the flipping type. For IBC Merge, the flipping type is inherited from the neighboring block without syntax signaling. Considering horizontal or vertical symmetry, the current block and the reference block are typically aligned horizontally or vertically. Therefore, when a horizontal flip is applied, the vertical component of the BV is not signaled and is presumed to be equal to 0. Similarly, when a vertical flip is applied, the horizontal component of the BV is not signaled and is presumed to be equal to 0.

[0341] To better utilize symmetry properties, a flip-aware BV adjustment method is applied to refine block vector candidates. For example, as Figure 47A (Horizontal flip) and Figure 47B As shown in (vertical flip), ( x nbr , y nbr )and( x cur , y cur () represents the coordinates of the center sample points of the neighboring blocks and the current block, respectively. BV nbr and BV cur These represent the block value (BV) of the neighboring block and the current block, respectively. When the neighboring block is encoded and decoded with a horizontal flip, instead of directly inheriting the BV from the neighboring block, BV cur The horizontal component is transmitted through the direction of BV nbr The horizontal component (represented as) BV nbr h The motion shift is added and calculated, i.e. BV cur h =2( x nbr - x cur ) + BV nbr hSimilarly, in the case where adjacent blocks are encoded and decoded with a vertical flip, BV cur The vertical component is through the direction BV nbr The vertical component (represented as) BV nbr v The motion shift is added and calculated, i.e. BV cur v =2( y nbr - y cur ) + BV nbr v .

[0342] 2.35. Intra-frame template matching Intra-frame template matching prediction (intra-frame TMP) is a special intra-frame prediction mode that copies the best prediction block from the reconstructed portion of the current frame, whose L-shaped template matches the current template. For a predefined search range, the encoder searches the reconstructed portion of the current frame for the template most similar to the current template and uses the corresponding block as the prediction block. The encoder then transmits the use of this mode via signaling, and the same prediction operation is performed on the decoder side.

[0343] The prediction signal is obtained by comparing the L-shaped causal nearest neighbors of the current block with... Figure 48 It is generated by matching another block in a predefined search region, which consists of the following parts: R1: Current CTU R2: Top left CTU, R3: Above CTU, R4: Left CTU.

[0344] SAD was used as the cost function.

[0345] Within each region, the decoder searches for the template with the minimum SAD for the current template and uses its corresponding block as the prediction block.

[0346] The dimensions of all regions (SearchRange_w, SearchRange_h) are set to be proportional to the block dimensions (BlkW, BlkH) to have a fixed number of SAD comparisons per pixel. That is: SearchRange_w = a * BlkW, SearchRange_h = a * BlkH.

[0347] in" "" is a constant that controls the trade-off between gain and complexity. In practice, " "Equals 5."

[0348] For CUs with width and height dimensions less than or equal to 64, the intra-frame template matching tool is enabled. The maximum CU size for intra-frame template matching is configurable.

[0349] When DIMD is not used in the current CU, the intra-template matching prediction mode is transmitted at the CU level via a dedicated flag.

[0350] 2.36. Intra-frame prediction fusion Intra-frame prediction fusion methods use multiple prediction values ​​generated from different modes / reference lines.

[0351] In subtest a, multiple intra-frame predictions are generated and then fused using a weighted average. The process of deriving the predictions to be used in the fusion process is described below: 1) For the intra-angle prediction mode in a single-mode case including TIMD and DIMD, the proposed method, by representing it as... Intra-prediction is derived by weighting the intra-prediction obtained from multiple reference rows, where It is an intra-frame prediction from the default reference line, and This is a prediction from the row above the default reference row. The weights are set to... .

[0352] 2) For TIMD modes with hybrid patterns, Used in the first mode ( ),and Used in the second mode ( ).

[0353] 3) For DIMD patterns with mixtures, the number of forecasts selected for the weighted average is increased from 3 to 6.

[0354] In subtest b, intra-frame prediction fusion is performed on the reference lines instead of the prediction blocks. The two reference lines (referred to as...) This is used for intra-frame prediction fusion. The corresponding intra-frame prediction angle is considered during the fusion process. Reference lines for merging ( Each value in ) is derived from the following formula: .

[0355] When the intra-frame mode has a non-integer slope (required reference sample interpolation) and the block size is greater than 16, the proposed intra-frame prediction fusion is applied to the luma block, used together with MRL, and not applied to blocks encoded / decoded by ISP. In the method studied in subtest a, PDPC is applied for the intra-frame prediction mode using the reference line closest to the current block.

[0356] 2.37. Template-based Multi-Reference Line Intra-Frame Prediction (TMRL) The proposed TMRL model includes the following aspects: a) Expanded reference line candidate list and intra-prediction mode candidate list The extended reference line candidate list used in this proposal is {1, 3, 5, 7, 12}. The restrictions on the top CTU line remain unchanged. The size of the intra-prediction mode candidate list is 10. The construction of the intra-prediction mode candidate list is similar to that of MPM. The differences are: Planar modes were excluded from the proposed list of intra-prediction mode candidates.

[0357] If the DC mode is not already included, add the DC mode after the modes of the 5 adjacent PUs and the DIMD mode.

[0358] Add with from Angle patterns with incremental angles (compared to existing angle patterns in the intra-prediction mode candidate list).

[0359] b) Construction of the TMRL candidate list There are 5 × 10 = 50 combinations of extended reference lines and allowed intra-frame prediction modes for the block. Since the extended reference lines start from reference line 1, the region covered by reference line 0 is used for template matching. Between prediction (generated from the 50 combinations) and reconstruction, for the template region (see... Figure 49 The SAD cost is calculated. The 20 combinations with the lowest SAD cost are selected in ascending order to form the TMRL candidate list.

[0360] c) Signaling of TMRL Instead of directly encoding and decoding the reference line and intra-frame mode, the index of the TMRL candidate list is encoded and decoded to indicate which combination of the reference line and prediction mode is used to encode and decode the current block. In the proposed TMRL mode, truncated Golomb-Rice encoding and decoding with a division by 4 is used to encode and decode the selected combination from the combination list. The binarization process and codewords are shown in Table 2-8.

[0361] Table 2-8 – Binarization process of TMRL indexes

[0362] d) Encoder-side modification Encoder-side modifications were tested to further improve encoding and decoding efficiency. For intra-blocks larger than 8×8, if no TMRL mode is selected via SATD comparison, an additional TMRL RDO is added.

[0363] 2.38. Geometric Partitioning Mode with Adaptive Blending (GPM) In VVC, the final predicted samples are generated by mixing the predictions of the two predicted signals using a weighted average. Two integer mixing matrices ( W 0 and W 1) Used. The weights in the GPM blending matrix are derived from the ramp function based on the displacement from the predicted sample location to the GPM segmentation boundary. The blending region size is fixed at 2 (2 samples on each side of the GPM segmentation boundary).

[0364] like Figure 50 As shown, the mixing process in the ECM is improved by adding four additional mixing region sizes (one-quarter, half, double, and four times the existing region size). CU-level flags are encoded and decoded to transmit the selected mixing region size via signal transmission. Furthermore, extended weighting precision is utilized, where the maximum value of the weights is changed from 8 (in VVC) to 32 to accommodate the extended mixing region sizes.

[0365] Figure 50 The ramp function for weighting GPM mixing is shown, based on the displacement (d) from the predicted sample location to the GPM segmentation boundary and the mixing region size (τ).

[0366] 2.39. Geometric Segmentation Pattern (GPM) with Template Matching (TM) Template matching is applied to GPM. When GPM mode is enabled for CU, the CU level flag is signaled to indicate whether TM is applied to the two geometric segments. For the motion information of each geometric segment, TM refinement is used. When TM is selected, a template is constructed using left-side, top-side, or left-side and top-side neighboring samples, as shown in Table 2-9, depending on the segmentation angle. Motion refinement is then performed by minimizing the difference between the current template and the template in the reference image using the same search style in Merge mode with half-pixel interpolation filters disabled.

[0367] Table 2-9 – Templates for the first and second geometric segments, where A indicates the use of the top sample point, L indicates the use of the left sample point, and L+A indicates the use of both the left and top sample points.

[0368]

[0369] The GPM candidate list is constructed as follows: 1. The interleaved list 0 MV candidates and list 1 MV candidates are derived directly from the regular merge candidate list, where list 0 MV candidates have a higher priority than list 1 MV candidates. A deduplication method based on an adaptive threshold according to the current CU size is applied to remove redundant MV candidates.

[0370] 2. The staggered list 1 MV candidates and list 0 MV candidates are further derived directly from the regular merge candidate list, where list 1 MV candidates have a higher priority than list 0 MV candidates. The same deduplication method using adaptive thresholding is also applied to remove redundant MV candidates.

[0371] 3. Zero MV candidates are filled until the GPM candidate list is full.

[0372] GPM-MMVD and GPM-TM are exclusively enabled to a single GPM CU. This is done first via signaling the GPM-MMVD syntax. When both GPM-MMVD control flags are false (i.e., GPM-MMVD is disabled for both GPM segments), the GPM-TM flag is signaled to indicate whether template matching is applied to both GPM segments. Otherwise (if at least one GPM-MMVD flag is true), the value of the GPM-TM flag is presumed to be false.

[0373] 2.40. GPM with inter-frame and intra-frame prediction In GPM with inter-frame and intra-frame prediction, the final prediction samples are generated by weighting the inter-frame and intra-frame prediction samples of the regions separated by each GPM. Inter-frame prediction samples are derived from the inter-frame GPM, while intra-frame prediction samples are derived from the intra-frame prediction mode (IPM) candidate list and the index from the encoder transmitted through the signal. The IPM candidate list size is predefined as 3. Available IPM candidates are the parallel angle mode (parallel mode) for GPM block boundaries, the vertical angle mode (vertical mode) for GPM block boundaries, and the planar mode, such as... Figure 51 As shown in (a) to (c). Furthermore, as... Figure 51 As shown in (d), the GPM with intra-frame and intra-frame prediction is limited to reduce signaling overhead for IPM and avoid increasing the size of the intra-frame prediction circuitry on the hardware decoder. Additionally, direct motion vectors and IPM storage are introduced in the GPM mixing region to further improve encoding and decoding performance.

[0374] Figure 51GPMs with inter-frame and intra-frame predictions are shown. Available IPM candidates are shown in (a) to (c). (d) An example of a GPM with intra-frame and intra-frame predictions is shown.

[0375] In IPM derivation based on DIMD and neighboring modes, parallel modes are registered first. Therefore, if no identical IPM candidates exist in the list, up to two IPM candidates derived from the decoder-side intra-frame mode derivation (DIMD) method and / or neighboring block derivation can be registered. As for neighboring mode derivation, up to five locations are available for neighboring blocks, but they are limited by the angles of GPM block boundaries that have already been used for GPM with template matching (GPM-TM), as shown in Table 2-10.

[0376] Table 2-10 – Positions of available neighboring blocks derived for IPM candidate based on the angle of the GPM block boundary. A and L represent the top and left sides of the predicted block.

[0377]

[0378] GPM-intraframe can be combined with GPM with Merge and Motion Vector Difference (GPM-MMVD). TIMD is used as an IPM candidate for GPM-intraframe to further improve encoding and decoding performance. Parallel modes can be registered first, followed by TIMD, DIMD, and IPM candidates from neighboring blocks.

[0379] 2.41. Template-matching-based reordering for GPM partitioning patterns In template-match-based reordering of GPM partition patterns, given the motion information of the current GPM block, the corresponding TM generation value of the GPM partition pattern is calculated. Then, all GPM partition patterns are reordered in ascending order based on their TM generation values. Instead of sending the GPM partition patterns, an index using a Golomb-Rice code is transmitted via signaling to indicate the exact location of the GPM partition pattern in the reordering list.

[0380] The reordering method for GPM partitioning patterns is a two-step process performed after the corresponding reference templates for the two GPM partitions in the encoding / decoding unit are generated, as follows: • Extend the GPM segmentation edge to the reference templates of the two GPM segments to generate 64 reference templates, and compute the corresponding TM cost for each of the 64 reference templates. • The TM generation values ​​based on the GPM partitioning pattern are reordered in ascending order, and the top 32 partitioning patterns are marked as available partitioning patterns.

[0381] like Figure 52As shown, the edges on the template are extended from the edges of the current CU, but the GPM blending process is not applied to the template regions across the edges.

[0382] After ascending reordering using the TM cost, the index is transmitted via signaling.

[0383] 2.42. Convolutional Cross-Component Model (CCCM) for Intra-Frame Prediction We propose applying a convolutional cross-component model (CCCM) in a spirit similar to the current CCLM model to predict chroma samples from reconstructed luminance samples. As with CCLM, when chroma downsampling is used, the reconstructed luminance samples are downsampled to match a lower-resolution chroma grid.

[0384] In addition, similar to CCLM, there are options for single-model or multi-model variants of CCCM. The multi-model variant uses two models: one model is derived for samples above the average luminance reference value, and the other model is for the remaining samples (following the spirit of the CCLM design). The multi-model CCCM mode can be selected for PUs with at least 128 available reference samples.

[0385] 2.42.1. Convolution Filter The proposed 7-tap convolutional filter consists of a 5-tap plus-shaped spatial component, a nonlinear term, and a bias term. The input to the filter's 5-tap spatial component comprises a center (C) luminance sample co-located with the chrominance sample to be predicted, and its upper / north (N), lower / south (S), left / west (W), and right / east (E) nearest neighbors, as shown below. Figure 53 As shown.

[0386] The nonlinear term P is expressed as the square of the center luminance sample C and scaled to the range of sample values ​​for the content: P = ( C*C + midVal )>>bitDepth That is, for 10 bits of content, it is calculated as: P = (C*C + 512)>>10.

[0387] The bias term B represents the scalar offset between the input and output (similar to the offset term in CCLM) and is set to an intermediate chroma value (512 for 10-bit content).

[0388] The output of the filter is calculated as the filter coefficients c. i The convolution with the input values ​​is then limited to the range of valid chromaticity samples: predChromaVal = c0C + c1N + c2S + c3E + c4W + c5P + c6B.

[0389] 2.42.2. Calculation of Filter Coefficients Filter coefficients c i It is calculated by minimizing the MSE between the predicted chromaticity samples and the reconstructed chromaticity samples in the reference region. Figure 54 The reference region is shown, consisting of six rows of chroma samples above and to the left of the PU. The reference region extends one PU width to the right of the PU boundary and one PU height below the PU boundary. The region is adjusted to include only available samples. The expansion of the region shown in blue is necessary to support the "side samples" of the plus-shaped spatial filter and is filled in unavailable areas.

[0390] MSE minimization is performed by computing the autocorrelation matrix for the luma input and the cross-correlation vector between the luma input and the chromaticity output. The autocorrelation matrix is ​​decomposed using LDL, and the final filter coefficients are computed using back-substitution. This process roughly follows the computation of ALF filter coefficients in ECM; however, LDL decomposition is chosen instead of Cholesky decomposition to avoid the use of square root operations. The proposed method uses only integer operations.

[0391] 2.42.3. Bitstream Signaling The use of this mode is signaled via PU-level flags encoded and decoded by CABAC. A new CABAC context is included to support this. When signaling is involved, CCCM is considered a sub-mode of CCLM. That is, the CCCM flag is signaled only when the intra-frame prediction mode is LM_CHROMA_IDX (to enable single-mode CCCM) or MMLM_CHROMA_IDX (to enable multi-mode CCCM).

[0392] 2.43. Gradient Linear Model (GLM) Compared to CCLM, GLM uses the gradient of luminance samples to derive a linear model, rather than downsampled luminance values. Specifically, when GLM is applied, the input to the CCLM process (i.e., downsampled luminance samples) is... Gradient of brightness sample points Replacement. Other parts of CCLM (e.g., parameter derivation, linear transformation of prediction samples) remain unchanged.

[0393]

[0394] For signaling, when CCLM mode is enabled to the current CU, two flags are transmitted separately for the Cb and Cr components to indicate whether GLM is enabled for each component; if GLM is enabled for a component, a syntax element is further transmitted to select one of the four gradient filters for gradient calculation.

[0395] • like Figure 55 As shown, four gradient filters are enabled for GLM.

[0396] 2.44. Temporal Block Vector Prediction Temporal BV Prediction (TBVP) is proposed to mimic TMVP. Temporal BV candidates are introduced into the IBC Merge / AMVP candidate list. The IBC Merge candidate list includes the regular IBC Merge candidate list, the IBC-TM Merge candidate list, and the IBC-MBVD basic candidate list.

[0397] The TBVP candidates are derived from the same time-domain location as the TMVP using complete deduplication. They are placed before the HMVP candidates.

[0398] 2.45. Copy-filling for IBC Copy fill can be applied to overlapping regions. Using copy fill, unreconstructed points in overlapping regions can be filled by copying their predicted points, such as... Figure 56 As shown, in the form of an equation, P'(x,y) = P(x+BVx, y+BVy) Where P'(x,y) is the filled sample at position (x,y), P(x+BVx, y+BVy) is the predicted sample, and (BVx,BVy) is the BV of the current block.

[0399] Copy fill is performed only when both the horizontal BV component and the vertical BV component are less than or equal to 0.

[0400] 3. Problem In current designs of IBCs with template matching, the template matching process is exactly the same as that for inter-frame prediction, including template shape / size, search strategy, and early termination method. These are well-designed for inter-frame prediction. However, it may not be optimal for IBCs. 4. Detailed Implementation The specific embodiments described below should be considered as examples for explaining general concepts. These embodiments should not be interpreted in a narrow sense. Furthermore, these embodiments can be combined in any way.

[0402] In this disclosure, intra-block copying (IBC) may not be limited to current IBC techniques, but can be interpreted as a technique that, in addition to conventional intra-prediction methods, utilizes samples in the current strip / slice / sub-picture / image / other video unit (e.g., CTU line) to obtain a reference (or predicted) block.

[0403] In the following discussion, IBC can be replaced by other codec tools that rely on encoded / decoded / or reconstructed information within the same region, such as palettes or intra-frame template matching.

[0404] Template matching for IBC 1. A template matching method for IBC is proposed that differs from template matching for inter-frame prediction.

[0405] a. In one example, the template shape / size can be different.

[0406] i. In one example, the template size for IBC can be equal to N, where N is an integer greater than 0, such as N=1, or 2, or 3, or 4, or 5, or 6, or 7, or 8.

[0407] ii. In one example, the template size of the left template may be different from the template size of the top template.

[0408] iii. In one example, a template with an L-shape can be used.

[0409] iv. In one example, the template shape / size may depend on the block size / dimension.

[0410] b. In one example, the search range (S1) used in template matching for IBC can be larger than the search range (S2) used for inter-frame prediction.

[0411] i. In one example, S1 is greater than S2.

[0412] 1) In one example, S1 is an integer greater than 8.

[0413] 2) In one example, S1 can be the entire IBC cache, which indicates that the region can be used for IBC.

[0414] ii. In one example, S1 can be determined adaptively.

[0415] 1) In one example, S1 can depend on the block size / dimension.

[0416] 2) In one example, S1 can depend on the resolution.

[0417] iii. Alternatively, S1 is less than or equal to S2.

[0418] c. In one example, the early termination method during template matching can be different.

[0419] d. In one example, the search methods can be different.

[0420] i. In one example, the shapes used during the search process can be different.

[0421] 1) In one example, a square shape can be used.

[0422] 2) In one example, a larger rhombus shape can be used.

[0423] a) In one example, the position used in the rhombus can be {(–N, 0), (0, –N), (N, 0), (0, N), (–M, –M), (–M, M), (M, –M), (M, M)}.

[0424] i. In one example, N=2 and M=1.

[0425] ii. In one example, N=3 and M=2.

[0426] iii. In one example, N=4 and M=3.

[0427] iv. In one example, N=5 and M=4.

[0428] v. In one example, N=6 and M=5.

[0429] b) In one example, more than one rhombus shape can be used. Example in Figure 57 It is shown in the middle.

[0430] 3) In one example, a cross shape can be used.

[0431] 4) In one example, the order of the shapes used during the search process can be different.

[0432] ii. In one example, the search method used in IntraTMP can be used.

[0433] 1) In one example, a coarse-to-fine search can be used.

[0434] e. In one example, whether and / or how to use template matching for IBC can depend on the video content, such as screen content or camera content.

[0435] f. In one example, the fractional block vector can be searched in template matching for IBC.

[0436] g. In one example, the above method can be applied to IntraTMP.

[0437] h. In one example, different vector resolutions can be used for IBC / IntraTMP and for TM for inter-frame prediction.

[0438] Non-adjacent candidates for IBC 2. Propose one or more non-adjacent video units that can be used to construct an IBC / IntraTMP candidate list.

[0439] a. In one example, the candidate list could refer to the IBC AMVP / Merge list.

[0440] b. In one example, the candidate list may refer to the list of IBC AMVP / Merge that are used for a particular codec tool.

[0441] i. In one example, the codec tool can refer to RR-IBC, IBC-MBVD, IBC TM AMVP / Merge, IBC-CIIP, IBC-GPM, IBC-LIC, copy padding for IBC, and DBV mode.

[0442] c. In one example, the candidate list may refer to the candidate list used for IntraTMP.

[0443] d. In one example, the candidate list can be constructed for the chromaticity components.

[0444] e. In one example, the position of non-adjacent video units can depend on the encoding / decoding information.

[0445] i. In one example, encoding / decoding information can refer to block size / dimension.

[0446] ii. In one example, one or more locations of non-adjacent video units defined for inter-frame prediction can be used, such as in Figure 24 middle.

[0447] iii. In one example, one or more locations of non-adjacent video units defined for non-adjacent affine prediction can be used, such as in Figure 43A and Figure 43B middle.

[0448] iv. In one example, the location of a non-adjacent video cell can be the same as the location used by inter-frame prediction.

[0449] v. In one example, the positions can be in a predefined order.

[0450] f. In one example, the order of the positions can be the same as the order of the specific codec tool.

[0451] i. In one example, codec tools can refer to inter-frame codec tools, such as AMVP, regular Merge, ADMVR, AMVP-Merge mode, affine AMVP, affine Merge, and GPM.

[0452] ii. Alternative sites, different orders of location can be used.

[0453] iii. In one example, which non-adjacent candidate is checked / added first may depend on codec information, such as the distance between the non-adjacent video unit (i.e., the non-adjacent candidate) and the current video unit. Let D1 represent the distance between the first non-adjacent candidate and the current video unit, and D2 represent the distance between the second non-adjacent candidate and the current video unit.

[0454] 1) In one example, distance can refer to horizontal distance, and / or vertical distance, and / or a function of horizontal and vertical distance.

[0455] 2) In one example, non-adjacent candidates that are close to the current video cell can be checked / added first.

[0456] a) In one example, when D1 is less than D2, the first non-adjacent candidate can be checked / added before the second non-adjacent candidate.

[0457] 3) In one example, non-adjacent candidates that are far from the current video cell can be checked / added first.

[0458] a) In one example, when D1 is greater than D2, the first non-adjacent candidate can be checked / added before the second non-adjacent candidate.

[0459] g. In one example, at most N non-adjacent candidates can be added to the IBC / IntraTMP candidate list.

[0460] i. In one example, N can be predefined, such as N=1, or 2, or 3, or 4, or 5, or 6, or 7, or 8, or 9, or 10.

[0461] ii. In one example, N can adaptively depend on encoding / decoding information, such as block size / dimension.

[0462] iii. In one example, N can be transmitted as a signal in a bitstream.

[0463] 1) In one example, N can be transmitted via signaling at the sequence level / picture group level / picture level / strip level / piece group level, such as in the sequence header / picture header / SPS / VPS / DPS / DCI / PPS / APS / strip header / piece group header.

[0464] h. In one example, when one or more non-adjacent video units are encoded or decoded using IBC or IntraTMP, encoding / decoding information (e.g., block vectors) can be used.

[0465] i. In one example, when one or more non-adjacent video units are encoded and decoded using neither IBC nor IntraTMP, the neighboring video units of the non-adjacent video units can be further utilized.

[0466] i. In one example, codec information (e.g., block vectors) from one or more non-adjacent video units can be reordered.

[0467] j. In one example, when constructing the IBC / IntraTMP candidate list using non-adjacent candidates, the codec information for a specific codec tool can be inherited.

[0468] i. In one example, the codec tool may refer to adaptive motion vector resolution and / or subpixel IBC and / or RR-IBC and / or IBC-LIC and / or filtered IBC or variants thereof.

[0469] ii. Alternatively, the codec information for a specific codec tool may not be inherited, but may be set to predefined values.

[0470] k. In one example, whether to use one or more non-adjacent video units to construct the candidate list can be determined by signal transmission, predefined, or deduced.

[0471] i. In one example, whether to use one or more non-adjacent video units to build the candidate list can depend on the block size / dimension.

[0472] l. In one example, when non-adjacent video units are encoded and decoded in a particular mode, their encoding and decoding information (e.g., block vectors) may not be used.

[0473] i. In one example, a specific mode could refer to RR-IBC or copy-fill mode.

[0474] ii. Alternatively, the encoding / decoding information can be modified before it is used.

[0475] 1) In one example, when non-adjacent video units are encoded and decoded using RR-IBC, the block vector can be modified in the same way as candidates or HMVP candidates from adjacent video units.

[0476] 2) Alternatively, the block vector can be modified using a different method than that used for candidates from neighboring candidates and HMVP candidates.

[0477] a) In one example, the conditions for modifying the codec information can be different, such as a threshold used to compare the distance between non-adjacent video units and the current unit.

[0478] b) In one example, the methods used to modify the codec information can be different.

[0479] m. In one example, one or more checks may be performed before adding non-adjacent candidates to the IBC / IntraTMP candidate list.

[0480] i. In one example, a validity check of the block vector can be performed.

[0481] 1) In one example, an invalid block vector could mean that the block vector is outside the IBC cache.

[0482] 2) In one example, when a non-adjacent candidate block vector is invalid, it is not allowed to be added to the IBC / IntraTMP candidate list.

[0483] ii. In one example, a similarity check of block vectors can be performed.

[0484] 1) In one example, similarity checks can be performed conditionally, where the conditions can be the same as those of other candidates.

[0485] iii. In one example, the first check can be performed before the second check.

[0486] 1) In one example, the first check could refer to the validity check of the block vectors, and the second check could refer to the similarity check of the block vectors.

[0487] 2) In another example, the first check could refer to a similarity check of the block vectors, and the second check could refer to a validity check of the block vectors.

[0488] In one example, the codec information of a first video unit encoded in a first codec mode can be used before a second video unit encoded in a second codec mode.

[0489] i. In one example, the first codec mode could refer to IBC, and the second codec mode could refer to IntraTMP.

[0490] ii. Alternatively, the first codec mode may refer to IntraTMP, and the second codec mode may refer to IBC.

[0491] o. In one example, when building the candidate list, non-adjacent positions can be checked after adjacent positions.

[0492] p. In one example, when building a candidate list, non-adjacent positions can be checked after examining potential candidates based on history.

[0493] q. In one example, non-adjacent locations can be checked before or after a particular type of candidate.

[0494] i. In one example, a particular type of candidate could refer to adjacent candidates and / or time-domain candidates and / or HMVP candidates and / or paired candidates.

[0495] 3. When using non-adjacent spatial domain candidates to construct a motion list, the question is raised: which candidate is checked / added to the motion? The list can depend on encoding / decoding information.

[0496] a. In one example, encoding / decoding information can refer to... The distance between a non-adjacent video cell (i.e., a non-adjacent candidate) and the current video cell.

[0497] i. In one example, distance can refer to horizontal distance, and / or vertical distance, and / or a function of horizontal and vertical distance.

[0498] b. In one example, candidates with smaller distances can be checked / added first.

[0499] i. Alternative sites: Candidates with greater distances can be checked / added first.

[0500] c. In one example, the motion list could refer to the inter-frame AMVP / Merge candidate list.

[0501] d. In one example, the sports list could refer to the IBC AMVP / Merge candidate list.

[0502] e. In one example, the motion list could refer to the list of motions used in intra-frame prediction or IntraTMP.

[0503] f. In one example, a motion list can be used for a specific codec tool.

[0504] g. In one example, the codec tool can refer to...CIIP (e.g., CIIP-plane, CIIP-TIMD, CIIP-TM), BCW (e.g., BCW index derived via TM), MMVD (e.g., MMVD or TM-based reordering for MMVD), Template Matching (TM), Affine (e.g., Affine-MMVD, TM-based reordering for Affine-MMVD), DMVR / Multi-pass DMVR, PROF, BDOF or sample-based BDOF, Adaptive Decoder-Side Motion Vector Refinement (ADMVR), OBMC or TM-based OBMC, MHP, GPM (e.g., GPM, GPM-TM, GPM-MMVD, GPM-intraframe), Bilateral / Template Matching AMVP-Merge mode or variants thereof.

[0505] Block size limit for building the IBC candidate list 4. Propose one or more candidates that can be excluded from video units to construct an IBC / IntraTMP candidate list.

[0506] a. In one example, the candidate list could be the candidate list defined in Project 2.

[0507] b. In one example, whether to use one or more candidates may depend on the block size / dimension.

[0508] i. In one example, M×N blocks, where M is not equal to N, for example M=4 or N=4.

[0509] ii. In one example, an N×N block, such as N=4 or N=8.

[0510] c. In one example, one or more candidates can refer to one or more spatial candidates, one or more non-adjacent spatial candidates, temporal candidates, sub-block-based candidates, HMVP candidates, or paired candidates.

[0511] d. Alternatively, all candidates may be allowed for use in video units to build the IBC / IntraTMP candidate list.

[0512] General aspects 5. In the above examples, a video unit can refer to a color component / sub-picture / strip / piece / code-decode tree unit (CTU) / CTU row / multiple CTUs / code-decode unit (CU) / prediction unit (PU) / transform unit (TU) / code-decode tree block (CTB) / code-decode block (CB) / prediction block (PB) / transform block (TB) / block / sub-block of a block / sub-region within a block / any other region containing more than one sample or pixel.

[0513] 6. Whether and / or how the methods disclosed above can be applied to be transmitted via signaling at the sequence level / picture group level / picture level / strip level / piece group level, such as in the sequence header / picture header / SPS / VPS / DPS / DCI / PPS / APS / strip header / piece group header.

[0514] 7. Whether and / or how the methods disclosed above can be applied to transmit signals at PB / TB / CB / PU / TU / CU / VPDU / CTU / CTU lines / strips / films / sub-images / other types of areas containing more than one sample point or pixel.

[0515] 8. Whether and / or how to apply the methods disclosed above may depend on the information from the encoding / decoding process, such as block size, color format, single / dual tree segmentation, color components, and stripe / image type.

[0516] As used herein, the term "video unit" or "video block" can refer to a sequence, picture, strip, slice, brick, sub-picture, codec tree unit (CTU) / codec tree block (CTB), CTU / CTB line, one or more codec units (CU) / codec blocks (CB), one or more CTU / CTB, one or more Virtual Pipeline Data Units (VPDU), or a sub-region within a picture / strip / slice / brick. In the following discussion, IntraTMP can be replaced by other codec tools that rely on encoded / decoded / reconstructed information within the same region, such as palettes or intra-block copy (IBC).

[0517] Figure 58 A flowchart of a method 5800 for video processing according to an embodiment of the present disclosure is shown. Method 5800 is implemented during the conversion between video units of a video and a bitstream of a video.

[0518] At box 5810, for the conversion between video units and the video bitstream, a candidate list for video units is determined based on one or more non-adjacent video units. The candidate list is either an intra-block copy (IBC) candidate list or an intra-template matching prediction (IntraTMP) candidate list. The positional order of the one or more non-adjacent video units is predefined or based on codec information. Template matching for IBC or IntraTMP differs from template matching for inter-frame prediction. In some embodiments, the positions of the one or more non-adjacent video units are in a predefined order.

[0519] At box 5820, the transformation is performed based on a candidate list. In some embodiments, the transformation may include encoding video units into a bitstream. Alternatively or additionally, the transformation may include decoding video units from the bitstream. In this way, it improves template matching for IBC, thereby improving encoding / decoding efficiency and performance.

[0520] In some embodiments, the order of the positions is the same as the order of the encoding / decoding tools. For example, the encoding / decoding tools are inter-frame encoding / decoding tools. In some embodiments, the encoding / decoding tools are one of the following: Advanced Motion Vector Prediction (AMVP), Regular Merge, Adaptive Decoder-Side Motion Vector Refinement (ADMVR), AMVP-Merge mode, Affine AMVP, Affine Merge, or Geometric Partitioning (GPM) mode.

[0521] In some embodiments, which non-adjacent candidate video units are examined or added first depends on codec information. In some embodiments, the codec information includes the distance between non-adjacent candidate video units and video units. In some embodiments, the distance between non-adjacent candidate video units and video units includes at least one of the following: the horizontal distance between non-adjacent candidate video units and video units, the vertical distance between non-adjacent candidate video units and video units, or a function of the horizontal and vertical distances between non-adjacent candidate video units and video units.

[0522] In some embodiments, non-adjacent candidate video units that are close to a video unit are checked or added first. For example, if a first distance between a first non-adjacent candidate video unit and a video unit is less than a second distance between a second non-adjacent candidate video unit and a video unit, then the first non-adjacent candidate video unit is checked or added before the second non-adjacent candidate video unit.

[0523] In some embodiments, non-adjacent candidates that are far from the video unit are checked or added first. For example, if a first distance between a first non-adjacent candidate video unit and a video unit is greater than a second distance between a second non-adjacent candidate video unit and a video unit, then the first non-adjacent candidate video unit is checked or added before the second non-adjacent candidate video unit. In some embodiments, different orders of positions are used.

[0524] In some embodiments, at most N non-adjacent video units are added to the candidate list, where N is an integer. In some embodiments, N is predefined. For example, N is equal to 1, or 2, or 3, or 4, or 5, or 6, or 7, or 8, or 9, or 10.

[0525] In some embodiments, N depends on the encoding / decoding information. In some embodiments, the encoding / decoding information includes the block size or block dimension.

[0526] In some embodiments, N is transmitted via signaling in the bitstream. In some embodiments, N is transmitted via signaling at one of the following: sequence level, picture group level, picture level, stripe level, or slice group level. In some embodiments, N is transmitted via signaling at one of the following: sequence header, picture header, sequence parameter set (SPS), video parameter set (VPS), dependency parameter set (DPS), decoding capability information (DCI), picture parameter set (PPS), adaptive parameter set (APS), stripe header, or slice group header.

[0527] In some embodiments, if one or more non-adjacent video units are used to determine the candidate list, the codec information of the codec tool is inherited. For example, the codec tool includes at least one of the following: adaptive motion vector resolution, a variant of adaptive motion vector resolution, subpixel IBC, a variant of subpixel IBC, reconstructed reordering IBC (RR-IBC), a variant of RR-IBC, IBC local illumination compensation (LIC), a variant of IBC-LIC, filtered IBC, or a variant of filtered IBC. In some other embodiments, the codec information of the codec tool is not inherited, but is set to predefined values.

[0528] In some embodiments, one or more checks are performed before adding one or more non-adjacent video units to the candidate list. In some embodiments, a block vector validity check is performed. In some embodiments, if a block vector is invalid, the block vector is outside the IBC cache. In some other embodiments, if a non-adjacent candidate's block vector is invalid, it is not allowed to be added to the candidate list.

[0529] In some embodiments, a block vector similarity check is performed. In some embodiments, the similarity check is performed based on conditions. The conditions can be the same as those for other candidate video units.

[0530] In some embodiments, the first check is performed before the second check. In some embodiments, the first check is a block vector validity check, and the second check is a block vector similarity check. In some other embodiments, the first check is a block vector similarity check, and the second check is a block vector validity check.

[0531] In some embodiments, the block vector is modified using a different approach than that used for candidates from neighboring candidates and history-based motion vector prediction (HMVP) candidates. In some embodiments, the conditions for modifying the codec information are different. For example, the conditions may include a threshold for comparing the distances between non-adjacent video units. In some embodiments, the manner in which the codec information is modified is different.

[0532] In some embodiments, non-adjacent locations are examined before or after a type of candidate. In some embodiments, the type of candidate includes at least one of the following: adjacent candidates, temporal candidates, HMVP candidates, or paired candidates.

[0533] In some embodiments, if non-adjacent spatial candidates are used to construct the motion list, which candidate is examined or added to the motion list depends on the codec information. In some embodiments, the motion list is an IBC AMVP candidate list or an IBC Merge candidate list. In some other embodiments, the motion list is used for intra-frame prediction or IntraTMP.

[0534] In some embodiments, the encoding / decoding information includes the distance between non-adjacent candidate video units and video units. For example, the distance includes at least one of the following: horizontal distance, vertical distance, or a function of horizontal and vertical distance.

[0535] In some embodiments, non-adjacent candidate video units with smaller distances are checked or added first. Alternatively, non-adjacent candidate video units with larger distances are checked or added first.

[0536] In some embodiments, the motion list is an inter-frame AMVP candidate list. Alternatively, the motion list is an inter-frame merge candidate list.

[0537] In some embodiments, a motion list is used in the codec tool. In some embodiments, the codec tool includes at least one of the following: Inter-Frame Intra-Frame Joint Prediction (CIIP) mode, a variant of CIIP mode, Bidirectional Prediction (BCW) mode with weighted codec unit (CU) level, a variant of BCW mode, Merge Mode with Motion Vector Difference (MMVD) mode, a variant of MMVD mode, Template Matching (TM) mode, a variant of TM mode, Affine mode, a variant of Affine mode, Decoder-Side Motion Vector Refinement (DMVR) mode, a variant of DMVR mode, Multi-pass DMVR mode, a variant of Multi-pass DMVR mode, Prediction Refinement with Optical Flow (PROF) mode, a variant of PROF mode, and Bidirectional Optical Flow (BDO). F) mode, variants of BDOF mode, sample-based BDOF mode, variants of sample-based BDOF mode, Adaptive Decoder-Side Motion Vector Refinement (ADMVR) mode, variants of ADMVR mode, Overlapping Block Motion Compensation (OBMC) mode, variants of OBMC mode, TM-based OBMC mode, variants of TM-based OBMC mode, Multiple Hypothesis Prediction (MHP) mode, variants of MHP mode, GPM mode, variants of GPM mode, bilateral matching AMVP-Merge mode, variants of bilateral matching AMVP-Merge mode, template matching AMVP-Merge mode or variants of template matching AMVP-Merge mode.

[0538] In some embodiments, the CIIP mode includes at least one of the following: CIIP-plane, CIIP-template-based intra-frame mode derivation (TIMD), or CIIP-TM. Alternatively or additionally, the BCW mode includes a BCW index derived via TM. Alternatively or additionally, the MMVD mode includes TM-based reordering for MMVD. Alternatively or additionally, the affine mode includes at least one of the following: affine-MMVD, TM-based reordering for affine MMVD.

[0539] In some embodiments, a video unit includes at least one of the following: color components, prediction blocks (PB), transform blocks (TB), codec blocks (CB), prediction units (PU), transform units (TU), codec tree blocks (CTB), codec units (CU), codec tree units (CTU), CTU rows, multiple sets of CTUs, stripes, slices, sub-pictures, blocks, sub-regions within blocks, or regions containing more than one sample point or pixel.

[0540] In some embodiments, the indication of whether and / or how to determine the candidate list of video units is indicated at one of the following: sequence level, picture group level, picture level, strip level, or slice group level. In some embodiments, the indication of whether and / or how to determine the candidate list of video units is indicated at one of the following: sequence header, picture header, sequence parameter set (SPS), video parameter set (VPS), dependency parameter set (DPS), decoding capability information (DCI), picture parameter set (PPS), adaptive parameter set (APS), strip header, or slice group header.

[0541] In some embodiments, method 5800 may further include: determining whether and / or how to determine a candidate list of video units based on at least one of the following: a message indicated in one of the following: DPS, SPS, VPS, PPS, APS, picture header, strip header, slice header, maximum codec unit (LCU), codec unit (CU), LCU line, LCU group, TU, PU block, video codec unit; the position of one of the following: CU, PU, ​​TU, block, video codec unit; the block dimension of the current block and / or its neighboring blocks; the block shape of the current block and / or its neighboring blocks; the encoded mode of the video unit; an indication of the color format; the codec tree structure; strip type; slice type; picture type; color components; temporal layer identity; and the standard grade or level or layer.

[0542] According to another embodiment of this disclosure, a non-transitory computer-readable recording medium is provided. This non-transitory computer-readable recording medium stores a bitstream of video generated by a method performed by a video processing apparatus. The method includes: determining a candidate list for the video units based on one or more non-adjacent video units, wherein the candidate list is an intra-block copy (IBC) candidate list or an intra-template matching prediction (IntraTMP) candidate list, wherein the positional order of the one or more non-adjacent video units is predefined or based on codec information; and generating a bitstream based on the candidate list.

[0543] According to further embodiments of this disclosure, a method for storing a bitstream of video is provided. The method includes: determining a candidate list for video units based on one or more non-adjacent video units, wherein the candidate list is an intra-block copy (IBC) candidate list or an intra-template matching prediction (IntraTMP) candidate list, and wherein the positional order of the one or more non-adjacent video units is predefined or based on codec information; generating a bitstream based on the candidate list; and storing the bitstream in a non-transitory computer-readable recording medium.

[0544] The embodiments of this disclosure can be described according to the following entries, and their features can be combined in any reasonable manner.

[0545] Item 1. A video processing method, comprising: a conversion between video units of a video and a bitstream of the video; determining a candidate list for the video units based on one or more non-adjacent video units of the video units, wherein the candidate list is an intra-block copy (IBC) candidate list or an intra-template matching prediction (IntraTMP) candidate list, wherein the positional order of the one or more non-adjacent video units is predefined or based on codec information; and performing the conversion based on the candidate list.

[0546] Item 2. According to the method described in Item 1, the positions of the one or more non-adjacent video units are in a predefined order.

[0547] Item 3. The method according to Item 1, wherein the order of the positions is the same as the order of the encoding / decoding tools.

[0548] Item 4. The method according to Item 3, wherein the encoding / decoding tool is an inter-frame encoding / decoding tool.

[0549] Item 5. The method according to Item 4, wherein the encoding / decoding tool is one of the following: Advanced Motion Vector Prediction (AMVP), Regular Merge, Adaptive Decoder-Side Motion Vector Refinement (ADMVR), AMVP-Merge mode, Affine AMVP, Affine Merge, or Geometric Segmentation Mode (GPM).

[0550] Item 6. According to the method described in Item 1, which non-adjacent candidate video units are checked or added first depends on the encoding / decoding information.

[0551] Item 7. The method according to Item 6, wherein the encoding / decoding information includes the distance between the non-adjacent candidate video units and the video unit.

[0552] Item 8. According to the method of Item 7, the distance between the non-adjacent candidate video unit and the video unit includes at least one of the following: the horizontal distance between the non-adjacent candidate video unit and the video unit, the vertical distance between the non-adjacent candidate video unit and the video unit, or a function of the horizontal distance and the vertical distance between the non-adjacent candidate video unit and the video unit.

[0553] Item 9. The method according to Item 7, wherein non-adjacent candidate video units close to the video unit are checked or added first.

[0554] Item 10. The method according to Item 9, wherein if a first distance between a first non-adjacent candidate video unit and the video unit is less than a second distance between a second non-adjacent candidate video unit and the video unit, then the first non-adjacent candidate video unit is checked or added before the second non-adjacent candidate video unit.

[0555] Item 11. The method according to Item 7, wherein non-adjacent candidates that are far from the video unit are first checked or added.

[0556] Item 12. The method according to Item 11, wherein if a first distance between a first non-adjacent candidate video unit and the video unit is greater than a second distance between a second non-adjacent candidate video unit and the video unit, then the first non-adjacent candidate video unit is checked or added before the second non-adjacent candidate video unit.

[0557] Item 13. The method described in Item 1, wherein different orders of positions are used.

[0558] Item 14. The method according to Item 1, wherein at most N non-adjacent video units are added to the candidate list, where N is an integer.

[0559] Item 15. The method described in Item 14, wherein N is predefined.

[0560] Item 16. The method according to Item 15, wherein N is equal to 1, or 2, or 3, or 4, or 5, or 6, or 7, or 8, or 9, or 10.

[0561] Item 17. The method according to Item 14, wherein N depends on the encoding / decoding information.

[0562] Item 18. The method according to Item 17, wherein the encoding / decoding information includes block size or block dimension.

[0563] Item 19. The method according to Item 14, wherein N is transmitted via signal in the bit stream.

[0564] Item 20. The method according to Item 19, wherein N is transmitted by signaling at one of the following: sequence level, picture group level, picture level, strip level, or slice group level.

[0565] Item 21. The method according to Item 19, wherein N is transmitted via signaling in one of the following: sequence header, picture header, sequence parameter set (SPS), video parameter set (VPS), dependency parameter set (DPS), decoding capability information (DCI), picture parameter set (PPS), adaptive parameter set (APS), strip header or slice header.

[0566] Item 22. The method according to Item 1, wherein if the one or more non-adjacent video units are used to determine the candidate list, the encoding and decoding information of the encoding and decoding tools is inherited.

[0567] Item 23. The method according to Item 22, wherein the encoding / decoding tool comprises at least one of the following: adaptive motion vector resolution, a variant of adaptive motion vector resolution, subpixel IBC, a variant of subpixel IBC, reconstruction reordering IBC (RR-IBC), a variant of RR-IBC, IBC local illumination compensation (LIC), a variant of IBC-LIC, filtered IBC, or a variant of filtered IBC.

[0568] Item 24. The method described in Item 1, wherein the encoding and decoding information of the encoding and decoding tools is not inherited, but is set to predefined values.

[0569] Item 25. The method according to Item 1, wherein one or more checks are performed before adding the one or more non-adjacent video units to the candidate list.

[0570] Item 26. The method according to Item 25, wherein a validity check of the block vector is performed.

[0571] Item 27. The method according to Item 26, wherein if the block vector is invalid, the block vector is outside the IBC cache.

[0572] Item 28. The method according to Item 26, wherein if a non-adjacent candidate block vector is invalid, it is not allowed to be added to the candidate list.

[0573] Item 29. The method according to Item 25, wherein a similarity check of block vectors is performed.

[0574] Item 30. The method according to Item 29, wherein the similarity check is performed based on conditions, wherein the conditions are the same as those of other candidate video units.

[0575] Item 31. The method according to Item 25, wherein the first check is performed before the second check.

[0576] Item 32. The method according to Item 31, wherein the first check is a validity check of the block vectors and the second check is a similarity check of the block vectors.

[0577] Item 33. The method according to Item 31, wherein the first check is a block vector similarity check and the second check is a block vector validity check.

[0578] Item 34. The method according to Item 1, wherein the block vector is modified using a different method than that used for candidates from neighboring candidates and history-based motion vector prediction (HMVP) candidates.

[0579] Item 35. The method described in Item 34, wherein the conditions for modifying the encoding / decoding information are different.

[0580] Item 36. The method according to Item 35, wherein the condition includes a threshold for comparing the distance between a non-adjacent video unit and the video unit.

[0581] Item 37. The method described in Item 34, wherein the manner in which the encoding and decoding information is modified is different.

[0582] Item 38. The method according to Item 1, wherein non-adjacent positions are checked before or after a type of candidate.

[0583] Item 39. The method according to Item 38, wherein the candidate of one type includes at least one of the following: adjacent candidate, temporal candidate, HMVP candidate, or paired candidate.

[0584] Item 40. The method according to Item 1, wherein if no adjacent spatial domain candidates are used to construct the motion list, then which candidate is checked or added to the motion list depends on the encoding / decoding information.

[0585] Item 41. The method according to Item 40, wherein the motion list is an IBC AMVP candidate list or an IBCMeerge candidate list.

[0586] Item 42. The method according to Item 40, wherein the encoding / decoding information includes the distance between non-adjacent candidate video units and the video unit.

[0587] Item 43. The method according to Item 42, wherein the distance includes at least one of the following: horizontal distance, vertical distance, or a function of horizontal distance and vertical distance.

[0588] Item 44. The method according to Item 40, wherein non-adjacent candidate video units with smaller distances are first checked or added.

[0589] Item 45. The method according to Item 40, wherein non-adjacent candidate video units with greater distance are checked or added first.

[0590] Item 46. The method according to Item 40, wherein the motion list is an inter-frame AMVP candidate list, or wherein the motion list is an inter-frame Merge candidate list.

[0591] Item 47. The method according to Item 40, wherein the motion list is used for intra-frame prediction or IntraTMP.

[0592] Item 48. The method according to Item 40, wherein the motion list is used by the encoding / decoding tool.

[0593] Item 49. The method according to Item 48, wherein the encoding / decoding tool comprises at least one of the following: Inter-Frame Intra-Frame Joint Prediction (CIIP) mode, a variant of CIIP mode, Bidirectional Prediction (BCW) mode with weighting at the codec unit (CU) level, a variant of BCW mode, Merge Mode with Motion Vector Difference (MMVD) mode, a variant of MMVD mode, Template Matching (TM) mode, a variant of TM mode, Affine mode, a variant of affine mode, Decoder-Side Motion Vector Refinement (DMVR) mode, a variant of DMVR mode, Multi-pass DMVR mode, a variant of Multi-pass DMVR mode, Prediction Refinement with Optical Flow (PROF) mode, a variant of PROF mode, Bidirectional Optical Flow. (BDOF) mode, variants of BDOF mode, sample-based BDOF mode, variants of sample-based BDOF mode, Adaptive Decoder-Side Motion Vector Refinement (ADMVR) mode, variants of ADMVR mode, Overlapping Block Motion Compensation (OBMC) mode, variants of OBMC mode, TM-based OBMC mode, variants of TM-based OBMC mode, Multiple Hypothesis Prediction (MHP) mode, variants of MHP mode, GPM mode, variants of GPM mode, Bilateral Matching AMVP-Merge mode, variants of Bilateral Matching AMVP-Merge mode, Template Matching AMVP-Merge mode or variants of Template Matching AMVP-Merge mode.

[0594] Item 50. The method according to Item 49, wherein the CIIP mode includes at least one of the following: CIIP-plane, CIIP-template-based intra-frame mode derivation (TIMD), or CIIP-TM, and / or wherein the BCW mode includes a BCW index derived by TM, and / or wherein the MMVD mode includes TM-based reordering for MMVD, and / or wherein the affine mode includes at least one of the following: affine-MMVD, TM-based reordering for affine MMVD.

[0595] Item 51. The method according to any one of items 1 to 50, wherein the video unit comprises at least one of the following: color component, prediction block (PB), transform block (TB), codec block (CB), prediction unit (PU), transform unit (TU), codec tree block (CTB), codec unit (CU), codec tree unit (CTU), CTU row, multiple sets of CTU, strip, slice, sub-picture, block, sub-region within a block, or region containing more than one sample point or pixel.

[0596] Item 52. The method according to any one of items 1 to 51, wherein the indication of whether to determine the candidate list of the video unit and / or how to determine the candidate list of the video unit is indicated at one of the following: sequence level, picture group level, picture level, strip level, or slice group level.

[0597] Item 53. The method according to any one of items 1 to 51, wherein the indication of whether to determine the candidate list of the video unit and / or how to determine the candidate list of the video unit is indicated in one of the following: sequence header, picture header, sequence parameter set (SPS), video parameter set (VPS), dependency parameter set (DPS), decoding capability information (DCI), picture parameter set (PPS), adaptive parameter set (APS), strip header or slice header.

[0598] Item 54. The method according to any one of items 1 to 51 further comprises: determining whether and / or how to determine the candidate list of the video unit based on at least one of the following: a message indicated in one of the following: DPS, SPS, VPS, PPS, APS, picture header, strip header, slice header, maximum codec unit (LCU), codec unit (CU), LCU row, LCU group, TU, PU block, video codec unit; the position of one of the following: CU, PU, ​​TU, block, video codec unit; the block dimension of the current block and / or its neighboring blocks; the block shape of the current block and / or its neighboring blocks; the encoded mode of the video unit; an indication of the color format; a codec tree structure; strip type; slice type; picture type; color components; temporal layer identity; a standard grade or level or layer.

[0599] Item 55. The method according to any one of items 1 to 54, wherein the conversion includes encoding the video unit into the bitstream.

[0600] Item 56. The method according to any one of items 1 to 54, wherein the conversion comprises decoding the video unit from the bitstream.

[0601] Item 57. 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 a method according to any one of items 1 to 56.

[0602] Item 58. A non-transitory computer-readable storage medium storing instructions that cause a processor to perform the method according to any one of items 1 to 56.

[0603] Item 59. A non-transitory computer-readable recording medium storing a bitstream of video generated by a method performed by means of an apparatus for video processing, wherein the method comprises: determining a candidate list for the video units based on one or more non-adjacent video units of the video units, wherein the candidate list is an intra-block copy (IBC) candidate list or an intra-template matching prediction (IntraTMP) candidate list, wherein the positional order of the one or more non-adjacent video units is predefined or based on encoding / decoding information; and generating the bitstream based on the candidate list.

[0604] Item 60. A method for storing a bitstream of video, comprising: determining a candidate list for video units based on one or more non-adjacent video units of video units of the video, wherein the candidate list is an intra-block copy (IBC) candidate list or an intra-template matching prediction (IntraTMP) candidate list, wherein the positional order of the one or more non-adjacent video units is predefined or based on encoding / decoding information; generating the bitstream based on the candidate list; and storing the bitstream in a non-transitory computer-readable recording medium.

[0605] Example device Figure 59 A block diagram of a computing device 5900 in which various embodiments of the present disclosure may be implemented is shown. The computing device 5900 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).

[0606] It should be understood that, Figure 59 The computing device 5900 shown is for illustrative purposes only and is not intended to imply any limitation on the functionality and scope of the embodiments of this disclosure.

[0607] like Figure 59As shown, computing device 5900 includes general-purpose computing device 5900. Computing device 5900 may include at least one or more processors or processing units 5910, memory 5920, storage unit 5930, one or more communication units 5940, one or more input devices 5950, and one or more output devices 5960.

[0608] In some embodiments, the computing device 5900 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 mobile phones, stations, units, devices, multimedia computers, multimedia tablet computers, internet nodes, communicators, desktop computers, laptop computers, notebook computers, netbook computers, tablet computers, personal communication system (PCS) devices, personal navigation devices, personal digital assistants (PDAs), audio / video players, digital cameras / camcorders, positioning devices, television receivers, radio receivers, e-book devices, gaming devices, or any combination thereof, and includes accessories and peripherals of these devices, or any combination thereof. It is conceivable that the computing device 5900 can support any type of interface to the user (such as "wearable" circuitry devices, etc.).

[0609] Processing unit 5910 can be a physical processor or a virtual processor, and can perform various processes based on programs stored in memory 5920. In a multiprocessor system, multiple processing units execute computer-executable instructions in parallel to improve the parallel processing capabilities of computing device 5900. Processing unit 5910 may also be referred to as a central processing unit (CPU), microprocessor, controller, or microcontroller.

[0610] Computing device 5900 typically includes various computer storage media. Such media can be any media accessible by computing device 5900, including but not limited to volatile and non-volatile media, or removable and non-removable media. Memory 5920 can be volatile memory (e.g., registers, cache, random access memory (RAM)), non-volatile memory (such as read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), or flash memory) or any combination thereof. Storage cell 5930 can be any removable or non-removable media and may include machine-readable media, such as memory, flash drives, disks, or other media that can be used to store information and / or data and can be accessed within computing device 5900.

[0611] The computing device 5900 may also include additional removable / non-removable storage media, volatile / non-volatile storage media. Although in Figure 59 Not shown, but may provide disk drives for reading from and / or writing to removable non-volatile disks, and optical disc drives for reading from and / or writing to removable non-volatile optical discs. In this case, each drive may be connected to a bus (not shown) via one or more data media interfaces.

[0612] Communication unit 5940 communicates with another computing device via a communication medium. Furthermore, the functionality of the components in computing device 5900 can be implemented by a single computing cluster or by multiple computing machines communicating via communication connections. Therefore, computing device 5900 can operate in a networked environment using logical connections to one or more other servers, networked personal computers (PCs), or other general-purpose network nodes.

[0613] Input device 5950 can be one or more of various input devices, such as a mouse, keyboard, trackball, voice input device, etc. Output device 5960 can be one or more of various output devices, such as a monitor, speaker, printer, etc. With the aid of communication unit 5940, computing device 5900 can also communicate with one or more external devices (not shown), such as storage devices and display devices. Computing device 5900 can also communicate with one or more devices that enable a user to interact with computing device 5900, or any device that enables computing device 5900 to communicate with one or more other computing devices (e.g., network card, modem, etc.), if needed. Such communication can be performed via an input / output (I / O) interface (not shown).

[0614] In some embodiments, some or all components of computing device 5900 may not be integrated into a single device, but may be deployed within a cloud computing architecture. In a cloud computing architecture, components may be provided remotely and may work together to perform the functions described herein. In some embodiments, cloud computing provides computing, software, data access, and storage services without requiring end users to know the physical location or configuration of the systems or hardware providing these services. In various embodiments, cloud computing provides services via a wide area network (WAN), such as the Internet, using suitable protocols. For example, a cloud computing provider offers applications via a WAN that can be accessed through a web browser or any other computing component. The software or components of the cloud computing architecture, along with the corresponding data, may be stored on servers at remote locations. Computing resources in a cloud computing environment may be consolidated or distributed across locations in remote data centers. Cloud computing infrastructure may provide services through shared data centers, although they may appear as a single access point for users. Therefore, cloud computing architectures can be used to provide the components and functions described herein from service providers at remote locations. Alternatively, they may be provided from traditional servers or may be installed directly or otherwise on client devices.

[0615] In embodiments of this disclosure, computing device 5900 can be used to implement video encoding / decoding. Memory 5920 may include one or more video codec modules 5925 having one or more program instructions. These modules can be accessed and executed by processing unit 5910 to perform the functions of the various embodiments described herein.

[0616] In an example embodiment of performing video encoding, input device 5950 may receive video data as input 5970 to be encoded. The video data may be processed, for example, by video codec module 5925 to generate an encoded bitstream. The encoded bitstream may be provided as output 5980 via output device 5960.

[0617] In an example embodiment of performing video decoding, input device 5950 may receive an encoded bitstream as input 5970. The encoded bitstream may be processed, for example, by a video codec module 5925 to generate decoded video data. The decoded video data may be provided as output 5980 via output device 5960.

[0618] While this disclosure has been specifically shown and described with reference to preferred embodiments, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of this application as defined by the appended claims. These changes are intended to be covered by the scope of this application. Therefore, the foregoing description of embodiments of this application is not intended to be limiting.

Claims

1. A video processing method, comprising: For the conversion between video units and the bitstream of the video, a candidate list is determined for each video unit based on one or more non-adjacent video units, wherein the candidate list is an intra-block copy (IBC) candidate list or an intra-template matching prediction (IntraTMP) candidate list, and the positional order of the one or more non-adjacent video units is predefined or based on encoding / decoding information; and The transformation is performed based on the candidate list.

2. The method of claim 1, wherein the positions of the one or more non-adjacent video units are in a predefined order.

3. The method according to claim 1, wherein the order of the positions is the same as the order of the encoding / decoding tools.

4. The method according to claim 3, wherein the encoding / decoding tool is an inter-frame encoding / decoding tool.

5. The method of claim 4, wherein the encoding / decoding tool is one of the following: Advanced Motion Vector Prediction (AMVP), Regular Merge, Adaptive Decoder-Side Motion Vector Refinement (ADMVR), AMVP-Merge mode, Affine AMVP, Affine Merge, or Geometric Partitioning (GPM).

6. The method of claim 1, wherein which non-adjacent candidate video units are checked or added first depends on the encoding / decoding information.

7. The method of claim 6, wherein the encoding / decoding information includes the distance between non-adjacent candidate video units and the video unit.

8. The method of claim 7, wherein the distance between the non-adjacent candidate video unit and the video unit includes at least one of the following: The horizontal distance between the non-adjacent candidate video units and the video unit. The vertical distance between the non-adjacent candidate video unit and the video unit, or The horizontal and vertical distances between the non-adjacent candidate video units and the video unit are functions of each other.

9. The method of claim 7, wherein non-adjacent candidate video units close to the video unit are checked or added first.

10. The method of claim 9, wherein if a first distance between a first non-adjacent candidate video unit and the video unit is less than a second distance between a second non-adjacent candidate video unit and the video unit, then the first non-adjacent candidate video unit is checked or added before the second non-adjacent candidate video unit.

11. The method of claim 7, wherein non-adjacent candidates that are far from the video unit are first checked or added.

12. The method of claim 11, wherein if a first distance between a first non-adjacent candidate video unit and the video unit is greater than a second distance between a second non-adjacent candidate video unit and the video unit, then the first non-adjacent candidate video unit is checked or added before the second non-adjacent candidate video unit.

13. The method of claim 1, wherein different orders of positions are used.

14. The method of claim 1, wherein at most N non-adjacent video units are added to the candidate list, where N is an integer.

15. The method of claim 14, wherein N is predefined.

16. The method of claim 15, wherein N is equal to 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10.

17. The method of claim 14, wherein N depends on the encoding / decoding information.

18. The method of claim 17, wherein the encoding / decoding information includes block size or block dimension.

19. The method of claim 14, wherein N is transmitted as a signal in the bit stream.

20. The method of claim 19, wherein N is transmitted via signaling at one of the following levels: sequence level, picture group level, picture level, strip level, or slice group level.

21. The method of claim 19, wherein N is transmitted via signaling in one of the following: sequence header, picture header, sequence parameter set (SPS), video parameter set (VPS), dependency parameter set (DPS), decoding capability information (DCI), picture parameter set (PPS), adaptive parameter set (APS), strip header or slice header.

22. The method of claim 1, wherein if the one or more non-adjacent video units are used to determine the candidate list, the encoding / decoding information of the encoding / decoding tool is inherited.

23. The method of claim 22, wherein the encoding / decoding tool comprises at least one of the following: Adaptive motion vector resolution, A variant of adaptive motion vector resolution, Subpixel IBC, A variant of subpixel IBC, Reconstructing the reordered IBC (RR-IBC). Variants of RR-IBC IBC Local Lighting Compensation (LIC) Variants of IBC-LIC Filtered IBC, or A variant of the filtered IBC.

24. The method of claim 1, wherein the encoding and decoding information of the encoding and decoding tools is not inherited, but is set to a predefined value.

25. The method of claim 1, wherein one or more checks are performed before adding the one or more non-adjacent video units to the candidate list.

26. The method of claim 25, wherein a validity check of the block vector is performed.

27. The method of claim 26, wherein if the block vector is invalid, the block vector is outside the IBC cache.

28. The method of claim 26, wherein if a non-adjacent candidate block vector is invalid, it is not allowed to be added to the candidate list.

29. The method of claim 25, wherein a similarity check of the block vectors is performed.

30. The method of claim 29, wherein the similarity check is performed based on conditions, wherein the conditions are the same as those for other candidate video units.

31. The method of claim 25, wherein the first check is performed before the second check.

32. The method of claim 31, wherein the first check is a block vector validity check, and the second check is a block vector similarity check.

33. The method of claim 31, wherein the first check is a block vector similarity check, and the second check is a block vector validity check.

34. The method of claim 1, wherein the block vector is modified using a different method than that used for candidates from neighboring candidates and history-based motion vector prediction (HMVP) candidates.

35. The method of claim 34, wherein the conditions for modifying the encoding / decoding information are different.

36. The method of claim 35, wherein the condition includes a threshold for comparing the distance between a non-adjacent video unit and the video unit.

37. The method of claim 34, wherein the manner of modifying the encoding / decoding information is different.

38. The method of claim 1, wherein non-adjacent positions are checked before or after a type of candidate.

39. The method of claim 38, wherein the candidate of one type comprises at least one of the following: Adjacent candidates, Temporal candidates, HMVP candidate, or Candidates in pairs.

40. The method of claim 1, wherein if no adjacent spatial domain candidates are used to construct the motion list, then which candidate is checked or added to the motion list depends on the encoding / decoding information.

41. The method of claim 40, wherein the motion list is an IBC AMVP candidate list or an IBCMeerge candidate list.

42. The method of claim 40, wherein the encoding / decoding information includes the distance between non-adjacent candidate video units and the video unit.

43. The method of claim 42, wherein the distance comprises at least one of the following: Horizontal distance Vertical distance, or Functions of horizontal and vertical distances.

44. The method of claim 40, wherein non-adjacent candidate video units with smaller distances are checked or added first.

45. The method of claim 40, wherein non-adjacent candidate video units with greater distance are checked or added first.

46. ​​The method of claim 40, wherein the motion list is an inter-frame AMVP candidate list, or wherein the motion list is an inter-frame Merge candidate list.

47. The method of claim 40, wherein the motion list is used for intra-frame prediction or IntraTMP.

48. The method of claim 40, wherein the motion list is used in an encoding / decoding tool.

49. The method of claim 48, wherein the encoding / decoding tool comprises at least one of the following: Inter-Frame Intra-Frame Joint Prediction (CIIP) mode, a variant of CIIP mode, Bidirectional Prediction (BCW) mode with weighted coding / decoding unit (CU) level, a variant of BCW mode, Merge mode with motion vector difference (MMVD) mode, a variant of MMVD mode, Template Matching (TM) mode, a variant of TM mode, Affine mode, a variant of affine mode, Decoder-Side Motion Vector Refinement (DMVR) mode, a variant of DMVR mode, Multi-pass DMVR mode, a variant of Multi-pass DMVR mode, Prediction Refinement with Optical Flow (PROF) mode, a variant of PROF mode, Bidirectional Optical Flow Prediction (PROF) mode, etc. Streaming (BDOF) mode, variants of BDOF mode, sample-based BDOF mode, variants of sample-based BDOF mode, Adaptive Decoder-Side Motion Vector Refinement (ADMVR) mode, variants of ADMVR mode, Overlapping Block Motion Compensation (OBMC) mode, variants of OBMC mode, TM-based OBMC mode, variants of TM-based OBMC mode, Multiple Hypothesis Prediction (MHP) mode, variants of MHP mode, GPM mode, variants of GPM mode, Bilateral Matching AMVP-Merge mode, variants of Bilateral Matching AMVP-Merge mode, Template Matching AMVP-Merge mode or variants of Template Matching AMVP-Merge mode.

50. The method of claim 49, wherein the CIIP mode comprises at least one of: CIIP-plane, CIIP-template-based intra-frame mode derivation (TIMD), or CIIP-TM, and / or The BCW pattern mentioned above includes the BCW index derived via TM, and / or The MMVD mode includes TM-based reordering for MMVD, and / or The affine mode includes at least one of the following: affine-MMVD, TM-based reordering for affine MMVD.

51. The method according to any one of claims 1 to 50, wherein the video unit comprises at least one of the following: Color components, Predicted blocks (PB). Transform block (TB) Code block (CB) Prediction Unit (PU) Transformer Unit (TU) Code-decode tree block (CTB). Codec Unit (CU) Code-decode tree unit (CTU) CTU line, Multiple CTUs strip, piece, Sub-images, piece, Sub-regions within a block, or A region containing more than one sample point or pixel.

52. The method according to any one of claims 1 to 51, wherein the indication of whether to determine the candidate list of the video unit and / or how to determine the candidate list of the video unit is indicated at one of the following: sequence level, Image group level, Image quality, strip level, or Film series level.

53. The method according to any one of claims 1 to 51, wherein the indication of whether to determine the candidate list of the video unit and / or how to determine the candidate list of the video unit is indicated in one of the following: Sequence header, Image header, Sequence Parameter Set (SPS) Video Parameter Set (VPS) Dependency Parameter Set (DPS) Decoding Capability Information (DCI) Image Parameter Set (PPS) Adaptive Parameter Set (APS) strip head, or The beginning of the film.

54. The method according to any one of claims 1 to 51, further comprising: Whether to determine the candidate list of the video units and / or how to determine the candidate list of the video units are based on at least one of the following: The message indicated in one of the following: DPS, SPS, VPS, PPS, APS, image header, strip header, slice header, maximum codec unit (LCU), codec unit (CU), LCU line, LCU group, TU, PU block, video codec unit. The location of one of the following: CU, PU, ​​TU, block, video codec unit. The block dimensions of the current block and / or its neighboring blocks. The block shape of the current block and / or its neighboring blocks. The encoded / decoded mode of the video unit, Indicators of color format, Encoder tree structure, Strip type, Film set type, Image type, Color components, Temporal layer identity, Standard grade, level, or tier.

55. The method according to any one of claims 1 to 54, wherein the conversion comprises encoding the video unit into the bitstream.

56. The method according to any one of claims 1 to 54, wherein the conversion comprises decoding the video unit from the bitstream.

57. An apparatus for video processing, comprising a processor and a non-transitory memory having instructions thereon, wherein the instructions, when executed by the processor, cause the processor to perform the method according to any one of claims 1 to 56.

58. A non-transitory computer-readable storage medium storing instructions that cause a processor to perform the method according to any one of claims 1 to 56.

59. A non-transitory computer-readable recording medium storing a bitstream of video generated by a method performed by means of a video processing apparatus, wherein the method includes: Based on one or more non-adjacent video units of the video unit, a candidate list is determined for the video unit, wherein the candidate list is an intra-block copy (IBC) candidate list or an intra-template matching prediction (IntraTMP) candidate list, and the positional order of the one or more non-adjacent video units is predefined or based on encoding / decoding information; and The bitstream is generated based on the candidate list.

60. A method for storing a bitstream of video, comprising: Based on one or more non-adjacent video units of the video unit, a candidate list is determined for the video unit, wherein the candidate list is an intra-block copy (IBC) candidate list or an intra-template matching prediction (IntraTMP) candidate list, and the positional order of the one or more non-adjacent video units is predefined or based on encoding and decoding information. The bitstream is generated based on the candidate list; as well as The bitstream is stored in a non-transitory computer-readable recording medium.

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