Inter prediction in region adaptive hierarchical transform coding

Abstract

A mechanism for processing video data is disclosed. In one example, when utilizing regional adaptive hierarchical transform (RAHT) in geometry-based point cloud compression (G-PCC), the mechanism includes determining to disable alternating current (AC) inter prediction based on direct current (DC) of a reference node, DC of a current node, and one or more thresholds. Conversion between the visual media data and the bitstream can then be performed with AC inter prediction disabled.

Description

[0001] Cross-references to related applications

[0002] This patent application claims the benefit of international patent application PCT / CN2023 / 106495, filed on July 10, 2023, which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to the generation, storage, and use of digital audio and video media information in file formats. Background Technology

[0004] Digital video accounts for the largest share of bandwidth used on the internet and other digital communication networks. As the number of connected user devices capable of receiving and displaying video increases, the bandwidth demand for digital video is likely to continue to grow. Summary of the Invention

[0005] The first aspect relates to a method for processing media data, comprising: when utilizing Region Adaptive Hierarchical Transformation (RAHT) in Geometry-Based Point Cloud Compression (G-PCC), based on a reference node (DC) ref DC of the current node (DC) cur The DC and one or more thresholds are used to determine whether AC inter-frame prediction is disabled; and if AC inter-frame prediction is disabled, the conversion between visual media data and bitstream is performed.

[0006] Alternatively, in any of the foregoing aspects, another implementation of that aspect provides disabling AC inter-frame prediction when the following conditions are met:

[0007]

[0008] Wherein, Th1 is the first threshold among one or more thresholds, and Th2 is the second threshold among one or more thresholds.

[0009] Alternatively, in any of the foregoing aspects, another implementation of that aspect provides that when performing AC inter-frame prediction in the transform domain, DC... ref It lies in the RAHT transform domain.

[0010] Optionally, in any of the above aspects, another implementation of that aspect provides a replacement condition based on the attribute value of the parent node of the current node and the attribute value of the parent node of the reference node.

[0011] Alternatively, in any of the above aspects, another implementation of that aspect provides replacing the DC with the sum of the attribute values ​​of the current node's parent nodes. cur And replace the DC with the sum of the attribute values ​​of the parent node of the reference node. ref.

[0012] Alternatively, in any of the above aspects, another implementation of that aspect provides replacing DC with the average of the attribute values ​​of the current node's parent node. cur And replace the DC with the average attribute value of the parent node of the reference node. ref .

[0013] Optionally, in any of the above aspects, another implementation of that aspect provides DC ref It is derived from one or more nodes in a reference point cloud (PC) sample.

[0014] Alternatively, in any of the above aspects, another implementation of that aspect provides that the sum of the attribute values ​​of the parent nodes of the reference node is derived from one or more nodes in the reference point cloud (PC) sample.

[0015] Alternatively, in any of the above aspects, another implementation of that aspect provides that the average value of the attribute values ​​of the parent node of the reference node is derived from one or more nodes in the reference point cloud (PC) sample.

[0016] Optionally, in any of the above aspects, another implementation of that aspect provides DC ref It is derived from the corresponding nodes in the reference point cloud (PC) sample.

[0017] Optionally, in any of the above aspects, another implementation of that aspect provides DC ref It is derived from the corresponding nodes after motion compensation.

[0018] Optionally, in any of the above aspects, another implementation of that aspect provides DC ref It is derived by interpolating at the location in the reference point cloud (PC) sample.

[0019] Alternatively, in any of the above aspects, another implementation of the aspect provides that the first threshold (Th1) and the second threshold (Th2) are fixed at the encoder and the decoder.

[0020] Alternatively, in any of the above aspects, another implementation of that aspect provides that a first threshold (Th1) and a second threshold (Th2) are transmitted to the decoder.

[0021] Alternatively, in any of the foregoing aspects, another implementation of that aspect provides that one or more thresholds are different for at least one of different sequences and different frames.

[0022] Alternatively, in any of the above aspects, another implementation of that aspect provides that one or more thresholds are different for different attribute channels.

[0023] Optionally, in any of the above aspects, another implementation of that aspect provides that for different regions and at least one of different RAHT layers, one or more thresholds are different.

[0024] Alternatively, in any of the foregoing aspects, another implementation of that aspect provides one or more thresholds that depend on one or more factors including quantization parameters and global motion.

[0025] Alternatively, in any of the foregoing aspects, another implementation of that aspect provides disabling AC inter-frame prediction when the following conditions are met:

[0026]

[0027] Where Th1 is the first threshold among one or more thresholds, and Th2 is the second threshold among one or more thresholds.

[0028] Alternatively, in any of the above aspects, another implementation of that aspect provides the use of interpolation techniques in the reference frame for AC inter-frame prediction when no reference node is present at the motion-compensated location.

[0029] Alternatively, in any of the foregoing aspects, another implementation of that aspect provides an interpolation technique including nearest neighbor interpolation.

[0030] Alternatively, in any of the above aspects, another implementation of that aspect provides nearest neighbor interpolation based on Euclidean distance.

[0031] Alternatively, in any of the above aspects, another implementation of that aspect provides nearest neighbor interpolation based on the nearest Morton code.

[0032] Alternatively, in any of the foregoing aspects, another implementation of that aspect provides an interpolation technique that depends on DC. cur .

[0033] Alternatively, in any of the foregoing aspects, another implementation of that aspect provides performing a search in a reference point cloud (PC) sample to determine the closest DC. cur The nodes of the DC.

[0034] Optionally, in any of the above aspects, another implementation of that aspect provides a method based on spatial distance and DC. cur With DC refThe difference between the two points determines the optimal reference node, where the spatial difference includes Euclidean distance or Morton code distance.

[0035] Optionally, in any of the above aspects, another embodiment of the aspect provides an interpolation technique including interpolation at a reference node, wherein the interpolation at the reference node is based on multiple nearest neighbors.

[0036] Alternatively, in any of the above aspects, another implementation of the aspect provides that each of a plurality of nearest neighbors is weighted based on the distance of that nearest neighbor to the interpolation point.

[0037] Alternatively, in any of the above aspects, another implementation of that aspect provides that the number of multiple nearest neighbors is fixed.

[0038] Alternatively, in any of the above aspects, another implementation of the aspect provides that the number of multiple nearest neighbors is based on at least one of the RAHT layer and the attribute channel.

[0039] Optionally, in any of the above aspects, another implementation of that aspect provides that one or more of a maximum number of nearest neighbors and a minimum number of nearest neighbors are transmitted to the decoder.

[0040] Optionally, in any of the above aspects, another implementation of that aspect provides determining one or more of a plurality of nearest neighbors that are unsuitable for the interpolation technique based on a qualification criterion, and disabling one or more of the nearest neighbors that are determined to be unsuitable.

[0041] Alternatively, in any of the above aspects, another implementation of that aspect provides the use of interpolation results to generate inter-frame prediction values.

[0042] Alternatively, in any of the above aspects, another implementation of that aspect provides deriving AC inter-frame prediction based on interpolation techniques, and then combining the AC inter-frame prediction with intra-frame prediction to obtain the final prediction.

[0043] Alternatively, in any of the above aspects, another implementation of that aspect provides a final prediction that includes the average of AC inter-frame prediction and intra-frame prediction.

[0044] Alternatively, in any of the foregoing aspects, another implementation of that aspect provides a final prediction comprising a weighted average of AC inter-frame prediction and intra-frame prediction, wherein the weights for different layers are predetermined or the weights are transmitted to the decoder.

[0045] Alternatively, in any of the above aspects, another implementation of that aspect provides for determining spatial-temporal predictions based on spatial neighbors in the current point cloud (PC) sample and neighbors in a reference PC sample.

[0046] Alternatively, in any of the above aspects, another implementation of that aspect provides weights for interpolation based on factors including at least one of temporal distance and spatial distance.

[0047] Alternatively, in any of the above aspects, another implementation of that aspect provides that the weights used for interpolation are fixed or transmitted to the decoder.

[0048] Optionally, in any of the foregoing aspects, another embodiment of that aspect provides whether and / or how to apply any of the disclosed methods to transmit signals from the encoder to the decoder in at least one of a bitstream, frame, slice, slice, or octree.

[0049] Optionally, in any of the foregoing aspects, another embodiment of that aspect provides whether and / or how any of the disclosed methods are applied based on encoding / decoding information including one or more of dimension, color format, color components, slice type, and image type.

[0050] Alternatively, in any of the foregoing aspects, another implementation of that aspect provides a conversion that includes encoding media data into a bitstream.

[0051] Alternatively, in any of the above aspects, another implementation of that aspect provides a conversion that includes decoding media data from a bitstream.

[0052] The second aspect relates to an apparatus for processing video data, comprising: a processor; and a non-transitory memory having instructions thereon, wherein the instructions, when executed by the processor, cause the processor to perform any of the disclosed methods.

[0053] The third aspect relates to a non-transitory computer-readable medium including a computer program product for use by a video codec device, the computer program product including computer-executable instructions stored on the non-transitory computer-readable medium, such that when executed by a processor, the video codec device performs any of the disclosed methods.

[0054] The fourth aspect relates to a non-transitory computer-readable recording medium storing a bitstream of video generated by a method performed by a video processing apparatus, wherein the method includes: when utilizing a region adaptive hierarchical transformation (RAHT) in geometry-based point cloud compression (G-PCC), based on a reference node (DC)ref DC of the current node (DC) cur The DC and one or more thresholds are used to determine whether AC inter-frame prediction is disabled; and to generate a bitstream with AC inter-frame prediction disabled.

[0055] The fifth aspect relates to a method for storing video bitstreams, comprising: when utilizing Region Adaptive Hierarchical Transformation (RAHT) in Geometry-Based Point Cloud Compression (G-PCC), based on a reference node (DC) ref DC of the current node (DC) cur The method determines whether to disable AC inter-frame prediction using DC and one or more thresholds; generates a bitstream with AC inter-frame prediction disabled; and stores the bitstream in a non-transitory computer-readable recording medium.

[0056] The sixth aspect relates to the methods, apparatus, or systems described in this disclosure.

[0057] For clarity, any of the embodiments described above may be combined with any one or more of the other embodiments described above to create new embodiments within the scope of this disclosure.

[0058] These and other features will become clearer from the following detailed description, taken in conjunction with the accompanying drawings and claims. Attached Figure Description

[0059] To gain a more complete understanding of this disclosure, reference is now made to the following brief description, taken in conjunction with the accompanying drawings and detailed description, wherein like reference numerals denote like parts.

[0060] Figure 1 This is an example of the parent node of each child node of the transformation unit node.

[0061] Figure 2 This is a block diagram illustrating an example video processing system.

[0062] Figure 3 This is a block diagram of an example video processing device.

[0063] Figure 4 This is a flowchart of an example method for video processing.

[0064] Figure 5 This is a block diagram illustrating an example video codec system.

[0065] Figure 6 This is a block diagram showing an example encoder.

[0066] Figure 7 This is a block diagram showing an example decoder.

[0067] Figure 8 This is a schematic diagram of an example encoder. Detailed Implementation

[0068] First, it should be understood that although illustrative implementations of one or more embodiments are provided below, the disclosed systems and / or methods can be implemented using any number of techniques, whether currently known or yet to be developed. This disclosure should not be limited in any way to the illustrative implementations, drawings, and techniques described below, including the exemplary designs and implementations described herein, but can be modified within the scope of the appended claims and their full equivalents.

[0069] 1. Preliminary Discussion

[0070] This disclosure relates to media file formats. Specifically, it relates to inter-frame prediction of point cloud attributes in region-adaptive hierarchical transformation. These ideas can be applied individually or in various combinations to any point cloud codec, whether standard or non-standard, such as geometry-based point cloud compression (G-PCC) under development.

[0071] 2. Abbreviation

[0072] G-PCC - Geometry-based Point Cloud Compression

[0073] MPEG - Moving Picture Experts Group

[0074] 3DG - 3D Graphics Codec

[0075] CFP - Call for Proposals

[0076] V-PCC - Video-based point cloud compression

[0077] RAHT - Region Adaptive Hierarchical Transformation

[0078] 3. Further discussion

[0079] MPEG is an abbreviation for Moving Picture Experts Group, one of the major standardization organizations for processing multimedia. In 2017, the MPEG 3D Graphics Codec Group (3DG) released a Call for Proposals (CFP) document to begin developing a point cloud codec standard [1]. The final standard will include two types of solutions. Video-based point cloud compression (V-PCC) is suitable for point sets with a relatively uniform point distribution [2]. Geometry-based point cloud compression (G-PCC) is suitable for sparser distributions [3]. Both V-PCC and G-PCC support encoding and decoding of single point clouds and sequences of point clouds.

[0080] A point cloud can contain geometric information and attribute information. Geometric information describes the geometric location of the data points. Attribute information records details of the data points, such as texture, normal vectors, and reflections.

[0081] 3.1 Regional Adaptive Hierarchical Transformation

[0082] In G-PCC, one of the point cloud attribute encoding / decoding tools is RAHT. RAHT is a transformation that uses attributes associated with nodes in lower levels of an octree to predict the attributes of nodes in the next level [4]. RAHT assumes that the location of the points is given at both the encoder and decoder. RAHT follows the octree backward from the leaf nodes to the root node, recombining the nodes into larger nodes at each step until the root node is reached. At each level of the octree, the nodes are processed in Morton order. Instead of combining all eight nodes at once at each decomposition, RAHT does so in three steps along each dimension (e.g., along z, then y, then x). If there are nodes in the octree... If there are several levels, then RAHT needs to The tree is traversed backwards at each level.

[0083] Make the level The node at is For integers . Through the and The combination is obtained by combining elements along the first dimension, which is an example. RAHT only processes occupied nodes. If one node in a pair is not occupied, the other node is promoted to the next level and not processed; that is, if the latter is the occupied node in the pair, then... The combination process is repeated until the root is reached. Note that the combination process generates lower-level nodes, which are the result of combining different numbers of voxels along the way. The nodes are combined to generate nodes. The number of nodes is the weight of that node. .

[0084] In two nodes (e.g.) and Each time ) is combined, their respective weights are used. and RAHT applies the following transformation:

[0085] ,

[0086] in, and as well as

[0087] .

[0088] Note that the transformation matrix is ​​constantly changing to adapt to the weights, that is, to adapt to each... The actual number of leaf nodes represented. Used to combine and form further nodes at lower levels. These are the actual high-pass coefficients to be encoded and transmitted, generated by the transformation. Furthermore, the weights are accumulated at the levels described above. In the example above:

[0089]

[0090] In the final stage, the roots of the tree, the remaining two voxels and Transformed into the final two coefficients:

[0091]

[0092] in, .

[0093] 3.2 Upsampling Transform Domain Prediction in RAHT

[0094] Figure 1 This is an example of the parent node of each child node of the transformation unit node.

[0095] Transform domain prediction is introduced to improve the encoding and decoding efficiency of RAHT[5]. RAHT consists of two parts.

[0096] First, the RAHT tree traversal is changed from the previous ascending method to a descent-based method, i.e., a tree of attributes and weights is constructed, and then RAHT is performed on both the encoder and decoder from the root to the leaf. This transformation is also performed in an octree node transformation unit with 2×2×2 child nodes. Within a node, the encoder transformation order is from leaf to root.

[0097] Secondly, for each child node of the transform unit, a corresponding predictive child node is generated by upsampling the previous transform level. In fact, only child nodes containing the last point will generate corresponding predictive child nodes. The transform unit containing 2×2×2 predictive child nodes is transformed and subtracted from the transform attributes on the encoder side.

[0098] Each child node of a transformation unit node is predicted by 7 parent-level nodes, including 3 collinear parent-level neighbor nodes, 3 coplanar parent-level neighbor nodes, and 1 parent node. Coplanar neighbors and collinear neighbors are the neighbors that share faces and edges with the current transformation unit node, respectively. Figure 1 The diagram shows the seven parent-level nodes of each child node of the transformation unit node.

[0099] Attributes of each child node Based on its distance from its parent node, it is predicted as follows:

[0100]

[0101] in, It is a property of a parent node of this child node, and It depends on the distance weight. In G-PCC, .

[0102] For the AC coefficients, the residuals will be predicted through signal transmission.

[0103] For DC coefficients, the coefficients are inherited from previous levels, which means that DC coefficients are transmitted through the signal without prediction.

[0104] 3.3 Attribute Inter-Frame Prediction in RAHT

[0105] Inter-frame prediction in RAHT is discussed in [6]. It is proposed to apply inter-frame prediction to the DC and AC coefficients in RAHT. The same octree decomposition is performed on the current frame and the reference frame.

[0106] For the first five layers, the same octree scan is performed on both frames. Before performing the backward octree scan, a point-to-point matching process is performed to ensure that nodes in the reference frame can establish corresponding one-to-one relationships with nodes in the current frame. Each point in the reference frame is matched to a point in the current frame using the "up-matching" method. The Morton value of the matched point is the smallest Morton value greater than the current point's Morton value.

[0107] For the DC coefficients, the residual between the DC coefficients for the root node of the current frame and the DC coefficients for the root node of the reference frame is calculated as follows:

[0108]

[0109] Will The signal is transmitted to the decoder to replace .

[0110] For each node in the first N layers, the average attribute of nodes at the same octree position in the reference frame is calculated as follows: And the corresponding AC coefficient is calculated as .

[0111] For the AC coefficients, the prediction residuals are transmitted via signal as follows:

[0112]

[0113]

[0114] if If it equals 0, then It is used for prediction in the original transform domain.

[0115] Another approach in GPCC is to perform predictions in the RAHT domain, rather than in attributes and space. Therefore, there are two types in GPCC: Type 0 performs inter-frame predictions in the RAHT domain, and Type 1 performs predictions in attributes and space.

[0116] 4. The technical problem solved by the disclosed technical solution

[0117] The example design for inter-frame prediction of point cloud attributes in Region Adaptive Hierarchical Transformation (RAHT) has the following problems.

[0118] First, in the example design, both the encoder and decoder have access to the DC of the current RAHT node and the reference node during AC prediction. However, this information is not utilized in the GPCC example design.

[0119] Second, in the example design, inter-frame prediction of the RAHT node is applied if and only if the RAHT node exists in the same position in the reference frame. This can be a strict condition and therefore needs to be modified.

[0120] 5. List of solutions and implementation examples

[0121] To address the issues mentioned above and other unmentioned problems, the methods outlined below are disclosed. These projects should be considered as examples for explaining general concepts, and not interpreted in a narrow sense. Furthermore, these solutions can be applied individually or in combination in any way.

[0122] In the following description, point cloud (PC) samples can refer to frames / subframes / images / subimages / slices / subslices / pieces, etc.

[0123] 1) Regarding question 1, a proposal is made based on the reference node (DC) ref DC of the current node (DC) cur DC and some thresholds disable AC inter-frame prediction.

[0124] a. In one example, AC inter-frame prediction can be disabled when the following conditions are met:

[0125]

[0126] b. In one example, when performing inter-frame prediction in the transform domain, DC ref It can be performed in the RAHT transform domain.

[0127] c. Alternatively, the conditions can be replaced based on the attribute values ​​of the current node's parent node and the attributes of the reference node's parent node.

[0128] i. In one example, DC cur It can be replaced by the sum of the attribute values ​​of the current node's parent node, and DC ref It can be replaced by the sum of the attribute values ​​of the parent node of the reference node.

[0129] ii. Alternative location, DC cur It can be replaced by the average of the attribute values ​​of the current node's parent node, and DC ref It can be replaced by the average of the attribute values ​​of the parent node of the reference node.

[0130] d. In one example, DC ref (Or equivalently, the sum / average of the attributes of the parent node of the reference node) can be derived from the nodes in the reference PC sample, as follows:

[0131] i. In one example, DC ref It can be derived from the corresponding node in the reference PC sample.

[0132] ii. In one example, DC ref It can be derived from the corresponding nodes after motion compensation.

[0133] iii. In one example, DC ref It can be derived by interpolating at the location in the reference PC sample.

[0134] e. In one example, thresholds Th1 and Th2 can be fixed at the encoder and decoder.

[0135] f. In one example, thresholds Th1 and Th2 can be sent to the decoder.

[0136] g. In one example, the threshold may differ for different scenarios:

[0137] i. For example, the threshold can be different for different sequences, frames, etc.

[0138] ii. For example, the threshold can be different for different attribute channels.

[0139] iii. For example, the threshold may be different for different regions, RAHT layers, etc.

[0140] iv. For example, the threshold can depend on other factors, such as QP, global motion, etc.

[0141] h. In one example, the condition can be replaced by less than (<) instead of less than or equal to (<). A similar principle applies to values ​​greater than 0.5.

[0142] 2) Regarding question 2, it is proposed that when there is no reference node at the motion compensation location, the constraints should be relaxed and interpolation techniques should be used in the reference frame for AC inter-frame prediction.

[0143] a. In one example, the interpolation technique could be nearest neighbor interpolation.

[0144] i. In one example, nearest neighbors can be based on Euclidean distance.

[0145] ii. In one example, nearest neighbors can be based on the nearest Morton code.

[0146] b. In one example, the interpolation may depend on the DC of the current node.

[0147] i. For example, a search can be performed in the reference PC sample to determine the node whose DC is closest to the current DC.

[0148] ii. For example, spatial distance (such as Euclidean or Morton code difference) and the difference between the current node's DC and the reference node's DC can be used together to determine the optimal reference node.

[0149] c. In one example, the interpolation at the reference node can be based on multiple nearest neighbors.

[0150] i. In one example, the nearest neighbor can be weighted based on its distance to the point being interpolated.

[0151] ii. In one example, the number of such nearest neighbors used for interpolation can be fixed.

[0152] iii. In one example, the number of such neighbors can vary and can depend on factors such as the RAHT layer, attribute channels, etc.

[0153] iv. In one example, the maximum or minimum number of nearest neighbors can be sent to the decoder.

[0154] d. In one example, interpolation can be applied in conjunction with previously disclosed eligibility criteria to disable the use of nearest neighbors that are not eligible according to the proposed criteria.

[0155] e. In one example, the interpolation result can be used to generate inter-frame predictions.

[0156] f. In one example, after deriving inter-frame prediction based on interpolation, inter-frame prediction can be further combined with intra-frame prediction to obtain the final prediction.

[0157] i. For example, the final prediction could be the average of two predictions.

[0158] ii. For example, the final prediction may be a weighted average, and the weights may be predetermined for different layers or may be explicitly sent to the decoder.

[0159] g. In one example, the spatial nearest neighbors in the current PC sample and the nearest neighbors in the reference PC sample can be jointly considered for joint spatial-temporal prediction.

[0160] i. The weights used for interpolation can depend on factors such as temporal distance and spatial distance.

[0161] ii. Weights can be fixed or can be explicitly sent to the decoder.

[0162] 3) Whether and / or how the above-disclosed methods are applied can be from the encoder to the decoder via signal transmission in a bitstream / frame / slice / segment / octree / etc.

[0163] 4) Whether and / or how to apply the methods disclosed above may depend on encoding and decoding information, such as dimensions, color format, color components, slice / image type.

[0164] 6. References

[0165] [1] MPEG 3DG and requirements, “Call for proposals for point cloud compression V2”, ISO / IEC JTC1 / SC29 WG11N16763.

[0166] [2] ISO / IEC JTC 1 / SC 29 / WG 07, "Information technology - Coded representation of immersive media - Part 5: Video codec based on visual volume (V3C) and video-based point cloud compression (V-PCC)", ISO / IEC 23090-5.

[0167] [3] ISO / IEC JTC 1 / SC 29 / WG 11, "Information technology - MPEG-I (code-decode representation of immersive media) - Part 9: geometry-based point cloud compression", ISO / IEC 23090-9:2020(E).

[0168] [4] Ricardo L. De Queiroz and Philip A. Chou, “3D point cloud compression using region-adaptive hierarchical transformation”, IEEE Transactions on Image Processing.

[0169] [5] S. Lasserre and D. Flynn, “On the use of attribute correlation to improve RAHT”, ISO / IEC JTC1 / SC29 / WG11 M47378.

[0170] [6] Y.-Z. Xu, W. Wang, K. Zhang, L. Zhang, [G-PCC][related to EE13.2][new proposal] Inter-frame prediction for RAHT attribute coding and decoding, ISO / IEC JTC1 / SC29 / WG7 m61083, October 2022.

[0171] Figure 2 This is a block diagram illustrating an example video processing system 4000 in which various techniques disclosed herein may be implemented. Various implementations may include some or all of the components of system 4000. System 4000 may include an input 4002 for receiving video content. The video content may be received in a raw or uncompressed format, such as 8 or 10-bit multi-component pixel values, or in a compressed or encoded format. Input 4002 may represent a network interface, a peripheral bus interface, or a storage interface. Examples of network interfaces include wired interfaces (such as Ethernet, Passive Optical Networking (PON), etc.) and wireless interfaces (such as Wi-Fi or cellular interfaces).

[0172] System 4000 may include an encoding / decoding component 4004 capable of implementing the various encoding / decoding or coding methods described in this disclosure. Encoding / decoding component 4004 can reduce the average bit rate from the video input 4002 to the output of encoding / decoding component 4004 to produce an encoded / decoded representation of the video. Encoding / decoding techniques are therefore sometimes referred to as video compression or video transcoding techniques. The output of encoding / decoding component 4004 may be stored or transmitted via a communication connection, such as that represented by component 4006. The stored or communicatively transmitted bitstream (or encoded / decoded) representation of the video received at input 4002 may be used by component 4008 to generate pixel values ​​or displayable video that is sent to display interface 4010. The process of generating user-visible video from the bitstream representation is sometimes referred to as video decompression. Furthermore, although some video processing operations are referred to as “encoding / decoding” operations or tools, it should be understood that encoding / decoding tools or operations used at the encoder will be followed by corresponding decoding tools or operations that inversely reproduce the encoding / decoding results by the decoder.

[0173] Examples of peripheral bus interfaces or display interfaces may include Universal Serial Bus (USB), High Definition Multimedia Interface (HDMI), or DisplayPort, etc. Examples of storage interfaces include Serial Advanced Technology Attachment (SATA), Peripheral Component Interconnect (PCI), Integrated Drive Electronics (IDE), etc. The technologies described in this disclosure can be embodied in a variety of electronic devices, such as mobile phones, laptops, smartphones, or other devices capable of performing digital data processing and / or video display.

[0174] Figure 3 This is a block diagram of an example video processing apparatus 4100. Apparatus 4100 can be used to implement one or more methods described herein. Apparatus 4100 can be embodied in a smartphone, tablet, computer, Internet of Things (IoT) receiver, etc. Apparatus 4100 may include one or more processors 4102, one or more memories 4104, and video processing circuitry 4106. Processor 4102 can be configured to implement one or more methods described in this disclosure. (Memory 4104 can be used to store data and code for implementing the methods and techniques described herein.) Video processing circuitry 4106 can be used to implement some of the techniques described in this disclosure in hardware circuitry. In some embodiments, video processing circuitry 4106 may be at least partially included in processor 4102, such as a graphics coprocessor.

[0175] Figure 4 This is a flowchart of an example method 4200 for video processing. In box 4202, method 4200 includes: when utilizing Region Adaptive Hierarchical Transformation (RAHT) in Geometry-Based Point Cloud Compression (G-PCC), based on a reference node (DC) ref DC of the current node (DC) cur The DC and one or more thresholds are used to determine whether AC inter-frame prediction is disabled. In box 4204, with AC inter-frame prediction disabled, a conversion between visual media data and a bitstream is performed. According to the example, the conversion in step 4204 may include encoding at the encoder or decoding at the decoder.

[0176] In an embodiment, method 4200 includes disabling AC inter-frame prediction when the following conditions are met:

[0177]

[0178] Wherein, Th1 is the first threshold among one or more thresholds, and Th2 is the second threshold among one or more thresholds.

[0179] In the embodiment, when performing AC inter-frame prediction in the transform domain, DC refIt lies within the RAHT transform domain. In an embodiment, method 4200 includes a replacement condition based on the attribute values ​​of the current node's parent node and the attribute values ​​of the reference node's parent node.

[0180] In an embodiment, method 4200 includes replacing the DC with the sum of the attribute values ​​of the current node's parent nodes. cur And replace the DC with the sum of the attribute values ​​of the parent node of the reference node. ref In an embodiment, method 4200 includes replacing the DC with the average of the attribute values ​​of the current node's parent node. cur And replace the DC with the average attribute value of the parent node of the reference node. ref .

[0181] In an embodiment, DC ref It is derived from one or more nodes in a reference point cloud (PC) sample. In an embodiment, the sum of the attribute values ​​of the parent nodes of the reference node is derived from one or more nodes in the reference point cloud (PC) sample. In an embodiment, the average of the attribute values ​​of the parent nodes of the reference node is derived from one or more nodes in the reference point cloud (PC) sample. In an embodiment, DC ref It is derived from the corresponding nodes in the reference point cloud (PC) sample.

[0182] In an embodiment, DC ref It is derived from the corresponding node after motion compensation. In the embodiment, DC ref It is derived by interpolation at locations in the reference point cloud (PC) sample. In an embodiment, the first threshold (Th1) and the second threshold (Th2) are fixed at the encoder and decoder. In an embodiment, the first threshold (Th1) and the second threshold (Th2) are transmitted to the decoder. In an embodiment, one or more thresholds are different for at least one of different sequences and different frames. In an embodiment, one or more thresholds are different for different attribute channels.

[0183] In this embodiment, one or more thresholds are different for different regions and at least one of different RAHT layers. In this embodiment, one or more thresholds depend on one or more factors including quantization parameters and global motion.

[0184] In an embodiment, method 4200 includes disabling AC inter-frame prediction when the following conditions are met:

[0185]

[0186] Where Th1 is the first threshold among one or more thresholds, and Th2 is the second threshold among one or more thresholds.

[0187] In an embodiment, method 4200 includes: when there is no reference node at the motion compensation location, using interpolation techniques in the reference frame for AC inter-frame prediction.

[0188] In some embodiments, the interpolation technique includes nearest neighbor interpolation. In some embodiments, nearest neighbor interpolation is based on Euclidean distance. In some embodiments, nearest neighbor interpolation is based on the nearest Morton code. In some embodiments, the interpolation technique depends on DC. cur In an embodiment, method 4200 includes performing a search in a reference point cloud (PC) sample to determine the closest DC. cur The nodes of the DC. In the embodiment, based on spatial distance and DC cur With DC ref The optimal reference node is determined by the difference between the two points, where the spatial difference includes Euclidean distance or Morton code distance.

[0189] In an embodiment, the interpolation technique includes interpolation at a reference node, wherein the interpolation at the reference node is based on a plurality of nearest neighbors. In an embodiment, each of the plurality of nearest neighbors is weighted based on its distance from the interpolation point. In an embodiment, the number of the plurality of nearest neighbors is fixed. In an embodiment, the number of the plurality of nearest neighbors is based on at least one of a RAHT layer and an attribute channel. In an embodiment, one or more of a maximum number of the plurality of nearest neighbors and a minimum number of the plurality of nearest neighbors are transmitted to the decoder.

[0190] In one embodiment, method 4200 includes determining one or more of a plurality of nearest neighbors that are unsuitable for the interpolation technique based on a qualification criterion, and disabling one or more of the nearest neighbors determined to be unsuitable. In another embodiment, method 4200 includes generating inter-frame prediction values ​​using the interpolation results. In yet another embodiment, method 4200 includes deriving AC inter-frame prediction based on the interpolation technique, and then combining the AC inter-frame prediction with intra-frame prediction to obtain a final prediction. In yet another embodiment, the final prediction includes the average of the AC inter-frame prediction and the intra-frame prediction.

[0191] In one embodiment, the final prediction includes a weighted average of AC inter-frame prediction and intra-frame prediction, wherein the weights are predetermined for different layers or transmitted to the decoder. In another embodiment, method 4200 includes determining a spatial-temporal prediction based on spatial neighbors in the current point cloud (PC) sample and neighbors in a reference PC sample. In another embodiment, the weights used for interpolation are based on a factor including at least one of temporal distance and spatial distance. In yet another embodiment, the weights used for interpolation are fixed or transmitted to the decoder.

[0192] In an embodiment, whether and / or how any of the disclosed methods are applied is to transmit signals from the encoder to the decoder in at least one of a bitstream, frame, slice, slice, or octree.

[0193] In an embodiment, whether and / or how any of the disclosed methods are applied is based on encoding / decoding information including one or more of dimension, color format, color components, slice type, and image type.

[0194] Method 4200 can be implemented in an apparatus for processing video data, including a processor and a non-transitory memory having instructions thereon, such as a video encoder 4400, a video decoder 4500, and / or an encoder 4600. In this case, the instructions, when executed by the processor, cause the processor to perform method 4200. Alternatively, method 4200 can be executed by a non-transitory computer-readable medium comprising a computer program product for use by a video encoding / decoding device. The computer program product includes computer-executable instructions stored on the non-transitory computer-readable medium, causing the video encoding / decoding device to perform method 4200 when executed by a processor.

[0195] Figure 5 This is a block diagram illustrating an example video encoding / decoding system 4300 that can utilize the techniques disclosed herein. The video encoding / decoding system 4300 may include a source device 4310 and a target device 4320. The source device 4310 generates encoded video data, and this source device 4310 may be referred to as a video encoding device. The target device 4320 can decode the encoded video data generated by the source device 4310, and this target device 4320 may be referred to as a video decoding device.

[0196] Source device 4310 may include video source 4312, video encoder 4314, and input / output (I / O) interface 4316. Video source 4312 may include sources such as video capture devices, interfaces for receiving video data from video content providers, and / or computer graphics systems for generating video data, or combinations thereof. Video data may include one or more pictures. Video encoder 4314 encodes the video data from video source 4312 to generate a bitstream. The bitstream may include a sequence of bits forming a codec representation of the video data. The bitstream may include codec pictures and associated data. Codec pictures are codec representations of pictures. Associated data may include sequence parameter sets, picture parameter sets, and other syntax structures. I / O interface 4316 may include a modulator / demodulator (modem) and / or a transmitter. Encoded video data may be transmitted directly to target device 4320 via network 4330 through I / O interface 4316. Encoded video data may also be stored on storage medium / server 4340 for access by target device 4320.

[0197] Target device 4320 may include I / O interface 4326, video decoder 4324, and display device 4322. I / O interface 4326 may include a receiver and / or a modem. I / O interface 4326 may acquire encoded video data from source device 4310 or storage medium / server 4340. Video decoder 4324 may decode the encoded video data. Display device 4322 may display the decoded video data to a user. Display device 4322 may be integrated with target device 4320 or may be external to target device 4320, wherein target device 4320 may be configured to interface with an external display device.

[0198] The video encoder 4314 and the video decoder 4324 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 further standards.

[0199] Figure 6 This is a block diagram illustrating an example of a video encoder 4400, which can be... Figure 5 The system 4300 shown includes a video encoder 4314. The video encoder 4400 can be configured to perform any or all of the techniques disclosed herein. The video encoder 4400 includes multiple functional components. The techniques described in this disclosure can be shared among the various components of the video encoder 4400. In some examples, a processor can be configured to perform any or all of the techniques described in this disclosure.

[0200] The functional components of the video encoder 4400 may include a segmentation unit 4401, a prediction unit 4402, a residual generation unit 4407, a transform unit 4408, a quantization unit 4409, an inverse quantization unit 4410, an inverse transform unit 4411, a reconstruction unit 4412, a buffer 4413, and an entropy coding unit 4414. The prediction unit 4402 may include a mode selection unit 4403, a motion estimation unit 4404, a motion compensation unit 4405, and an intra-frame prediction unit 4406.

[0201] In other examples, the video encoder 4400 may include more, fewer, or different functional components. In one example, the prediction unit 4402 may include an intra-block copy (IBC) unit. The IBC unit can perform prediction in an IBC mode, where at least one reference picture is the picture in which the current video block is located.

[0202] Furthermore, some components such as the motion estimation unit 4404 and the motion compensation unit 4405 can be highly integrated, but for illustrative purposes, they are shown separately in the example of the video encoder 4400.

[0203] The segmentation unit 4401 can segment an image into one or more video blocks. The video encoder 4400 and the video decoder 4500 can support various video block sizes.

[0204] The mode selection unit 4403 can select one of several encoding / decoding modes (intra-frame encoding / decoding or inter-frame encoding / decoding), for example, based on error results, and provide the resulting intra-frame or inter-frame encoded / decoded block to the residual generation unit 4407 to generate residual block data, and to the reconstruction unit 4412 to reconstruct the coded block for use as a reference image. In some examples, the mode selection unit 4403 can select an intra-frame / inter-frame joint prediction (CIIP) mode, where prediction is based on inter-frame prediction signals and intra-frame prediction signals. In the case of inter-frame prediction, the mode selection unit 4403 can also select a resolution for the block based on motion vectors (e.g., sub-pixel precision or integer pixel precision).

[0205] To perform inter-frame prediction on the current video block, motion estimation unit 4404 can generate motion information for the current video block by comparing one or more reference frames from buffer 4413 with the current video block. Motion compensation unit 4405 can determine the predicted video block for the current video block based on the motion information and decoded samples of images from buffer 4413 other than the image associated with the current video block.

[0206] The motion estimation unit 4404 and the motion compensation unit 4405 can perform different operations on the current video block, for example, depending on whether the current video block is in an I-band, P-band, or B-band.

[0207] In some examples, motion estimation unit 4404 can perform unidirectional prediction on the current video block, and can search for reference images in list 0 or list 1 to find a reference video block for the current video block. Motion estimation unit 4404 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 4404 can output the reference index, prediction direction indicator, and motion vector as motion information for the current video block. Motion compensation unit 4405 can generate a predicted video block for the current block based on the reference video block indicated by the motion information of the current video block.

[0208] In other examples, motion estimation unit 4404 can perform bidirectional prediction on the current video block. Motion estimation unit 4404 can search for reference images in list 0 to find a reference video block for the current video block, and can also search for reference images in list 1 to find another reference video block for the current video block. Motion estimation unit 4404 can then generate reference indices indicating the reference images containing the reference video blocks in lists 0 and 1, and motion vectors indicating the spatial displacement between the reference video blocks and the current video block. Motion estimation unit 4404 can output the reference index and motion vector of the current video block as motion information for the current video block. Motion compensation unit 4405 can generate a predicted video block for the current video block based on the reference video blocks indicated by the motion information of the current video block.

[0209] In some examples, the motion estimation unit 4404 can output a complete set of motion information for use in the decoder's decoding process. In some examples, the motion estimation unit 4404 may not output a complete set of motion information for the current video. Instead, the motion estimation unit 4404 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 4404 may determine that the motion information of the current video block is sufficiently similar to the motion information of neighboring video blocks.

[0210] In one example, the motion estimation unit 4404 may indicate a value to the video decoder 4500 in the syntax structure associated with the current video block, which indicates that the current video block has the same motion information as another video block.

[0211] In another example, motion estimation unit 4404 may 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 4500 may use the motion vector of the indicated video block and the motion vector difference to determine the motion vector of the current video block.

[0212] As discussed above, the video encoder 4400 can transmit motion vectors via signaling in a predictive manner. Two examples of predictive signaling techniques that can be implemented by the video encoder 4400 include Advanced Motion Vector Prediction (AMVP) and Merge Pattern Signaling.

[0213] Intra-prediction unit 4406 can perform intra-prediction on the current video block. When intra-prediction unit 4406 performs intra-prediction on the current video block, it can generate prediction data for the current video block based on decoded samples of 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.

[0214] The residual generation unit 4407 can generate residual data for the current video block by subtracting the predicted video block of the current video block 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.

[0215] In other examples, there may be no residual data for the current video block, such as in skip mode, and the residual generation unit 4407 may not perform subtraction operations.

[0216] Transform unit 4408 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.

[0217] After the transform unit 4408 generates a transform coefficient video block associated with the current video block, the quantization unit 4409 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.

[0218] The inverse quantization unit 4410 and the inverse transform unit 4411 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 4412 can add the reconstructed residual video block to the corresponding samples of one or more predicted video blocks generated by the prediction unit 4402 to generate a reconstructed video block associated with the current block for storage in the buffer 4413.

[0219] After the video block is reconstructed by reconstruction unit 4412, a loop filtering operation can be performed to reduce video block artifacts in the video block.

[0220] Entropy encoding unit 4414 can receive data from other functional components of video encoder 4400. When entropy encoding unit 4414 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.

[0221] Figure 7 This is a block diagram illustrating an example of a video decoder 4500, which can be... Figure 5 The system 4300 shown includes a video decoder 4324. The video decoder 4500 can be configured to perform any or all of the techniques disclosed herein. In the example shown, the video decoder 4500 includes multiple functional components. The techniques described in this disclosure can be shared among the various components of the video decoder 4500. In some examples, a processor can be configured to perform any or all of the techniques described in this disclosure.

[0222] In the example shown, the video decoder 4500 includes an entropy decoding unit 4501, a motion compensation unit 4502, an intra-frame prediction unit 4503, an inverse quantization unit 4504, an inverse transform unit 4505, a reconstruction unit 4506, and a buffer 4507. In some examples, the video decoder 4500 can perform a decoding process that is the overall inverse of the encoding process described with respect to the video encoder 4400.

[0223] The entropy decoding unit 4501 can retrieve the encoded bitstream. The encoded bitstream may include entropy-encoded video data (e.g., encoded video data blocks). The entropy decoding unit 4501 can decode the entropy-encoded video data, and based on the entropy-decoded video data, the motion compensation unit 4502 can determine motion information including motion vectors, motion vector precision, reference image list index, and other motion information. The motion compensation unit 4502 can determine this information, for example, by executing AMVP and Merge modes.

[0224] The motion compensation unit 4502 can generate motion compensation blocks, possibly performing interpolation based on an interpolation filter. The identifier of the interpolation filter to be used, with sub-pixel accuracy, can be included in the syntax element.

[0225] The motion compensation unit 4502 can use the interpolation filter used by the video encoder 4400 during the encoding of a video block to calculate the interpolation for sub-integer pixels of the reference block. The motion compensation unit 4502 can determine the interpolation filter used by the video encoder 4400 based on the received syntax information, and the motion compensation unit 4502 can use the interpolation filter to generate a prediction block.

[0226] The motion compensation unit 4502 may use some syntax information to determine the size of the blocks of frames and / or stripes used to encode the encoded video sequence, segmentation information describing how each macroblock of the picture of the encoded video sequence is segmented, a mode indicating how each segment is encoded, one or more reference frames (and a list of reference frames) for each inter-frame codec block, and other information for decoding the encoded video sequence.

[0227] Intra-prediction unit 4503 can use, for example, an intra-prediction mode received in the bitstream to form prediction blocks from spatially adjacent blocks. Inverse quantization unit 4504 inverse quantizes (i.e., dequantizes) the quantized video block coefficients provided in the bitstream and decoded by entropy decoding unit 4501. Inverse transform unit 4505 applies the inverse transform.

[0228] The reconstruction unit 4506 can add the residual block to the corresponding predicted block generated by the motion compensation unit 4502 or the intra-frame prediction unit 4503 to form a decoded block. If necessary, a deblocking filter can also be applied to filter the decoded block to remove block artifacts. The decoded video block is then stored in a buffer 4507, which provides a reference block for subsequent motion compensation / intra-frame prediction and also generates decoded video for presentation on a display device.

[0229] Figure 8 This is a schematic diagram of an example encoder 4600. Encoder 4600 is suitable for implementing VVC techniques. Encoder 4600 includes three loop filters: a deblocking filter (DF) 4602, a sample adaptive compensation (SAO) 4604, and an adaptive loop filter (ALF) 4606. Unlike DF 4602, which uses predefined filters, SAO 4604 and ALF 4606 utilize the original samples of the current image, respectively, by adding an offset and by applying a finite impulse response (FIR) filter, and by utilizing the encoded / decoded side information through signal transmission offset and filter coefficients to reduce the mean square error between the original and reconstructed samples. ALF 4606 is located in the final processing stage of each image and can be considered as a tool for attempting to capture and repair artifacts caused by previous stages.

[0230] The encoder 4600 also includes an intra-frame prediction component 4608 and a motion estimation / compensation (ME / MC) component 4610 configured to receive input video. The intra-frame prediction component 4608 is configured to perform intra-frame prediction, while the ME / MC component 4610 is configured to perform inter-frame prediction using a reference image obtained from a reference image buffer 4612. Residual blocks from inter-frame or intra-frame prediction are fed into a transform (T) component 4614 and a quantization (Q) component 4616 to generate quantized residual transform coefficients, which are then fed into an entropy encoder / decoder component 4618. The entropy encoder / decoder component 4618 entropy-encodes and decodes the prediction results and quantized transform coefficients and transmits them toward a video decoder (not shown). The quantization component output from the quantization component 4616 can be fed into an inverse quantization (IQ) component 4620, an inverse transform component 4622, and a reconstruction (REC) component 4624. REC component 4624 is able to output images to DF 4602, SAO 4604 and ALF 4606 for filtering before these images are stored in reference image buffer 4612.

[0231] The following is a list of some preferred solutions.

[0232] 1. A method for processing media data, comprising: via a reference node (DC) refDC of the current node (DC) cur The DC and one or more thresholds disable AC inter-frame prediction, determine the application of Region Adaptive Hierarchical Transform (RAHT) in geometry-based point cloud compression (G-PCC), and perform conversion between visual media data and bitstream based on RAHT.

[0233] 2. The method according to Solution 1, wherein AC inter-frame prediction is disabled when the following conditions are met:

[0234]

[0235] 3. The method according to any one of solutions 1-2, wherein when performing inter-frame prediction in the transform domain, DC ref It lies in the RAHT transform domain.

[0236] 4. The method according to any one of solutions 1-3, wherein the condition is replaced based on the attribute value of the current node's parent node and the attribute of the reference node's parent node, or wherein DC cur Replaced by the sum of the attribute values ​​of the current node's parent node, and DC ref Replaced by the sum of the attribute values ​​of the parent node of the reference node, or where DC is... cur Replaced by the average of the attribute values ​​of the current node's parent node, and DC ref Replaced by the average of the attribute values ​​of the parent node of the reference node.

[0237] 5. The method according to any one of solutions 1-4, wherein DC ref The sum / average of the attributes of the reference parent node are derived from one or more nodes in the reference point cloud (PC) sample, or where DC ref Derived from the corresponding node in the reference PC sample, or from the DC... ref Derived from the corresponding nodes after motion compensation, or from DC within them. ref The derivation is achieved by interpolation at a location in the reference PC sample.

[0238] 6. The method according to any one of solutions 1-5, wherein thresholds Th1 and Th2 are fixed at the encoder and decoder, or wherein thresholds Th1 and Th2 are sent to the decoder.

[0239] 7. The method according to any one of solutions 1-6, wherein the threshold is different for different scenarios, or wherein the threshold is different for different sequences or frames, or wherein the threshold is different for different attribute channels, or wherein the threshold is different for different regions or RAHT layers, or wherein the threshold depends on other factors including quantization parameters (QP) or global motion.

[0240] 8. The method according to any one of solutions 1-7, wherein the condition is less than or greater than.

[0241] 9. The method according to any one of solutions 1-8, wherein when there is no reference node at the motion-compensated location, interpolation techniques are used in the reference frame for AC inter-frame prediction.

[0242] 10. The method according to any one of solutions 1-9, wherein the interpolation technique employs nearest neighbor interpolation, or wherein the nearest neighbor is based on Euclidean distance, or wherein the nearest neighbor is based on the nearest Morton code.

[0243] 11. The method according to any one of solutions 1-10, wherein the interpolation depends on the DC of the current node, or wherein a search is performed in the reference PC sample to determine the node whose DC is closest to the current DC, or wherein the spatial distance of the Euclidean or Morton code difference and the difference between the DC of the current node and the DC of the reference node are jointly used to determine the optimal reference node.

[0244] 12. The method according to any one of solutions 1-11, wherein the interpolation at the reference node is based on multiple nearest neighbors, or wherein the nearest neighbors are weighted based on their distance from the interpolation point, or wherein the number of such nearest neighbors used for interpolation is fixed, or wherein the number of such nearest neighbors is different and depends on factors including the RAHT layer or attribute channels, or wherein a maximum or minimum number of nearest neighbors is sent to the decoder.

[0245] 13. The method according to any one of solutions 1-12, wherein interpolation is applied in conjunction with qualification criteria to disable the use of nearest neighbors that are not suitable according to the proposed criteria.

[0246] 14. The method according to any one of solutions 1-13, wherein the interpolation result is used to generate inter-frame prediction values.

[0247] 15. The method according to any one of solutions 1-14, wherein after deriving inter-frame prediction based on inter-frame inter-frame prediction, the inter-frame prediction is further combined with intra-frame prediction to obtain a final prediction, or wherein the final prediction is the average of the two predictions, or wherein the final prediction is a weighted average, and the weights are predetermined for different layers or are explicitly sent to the decoder.

[0248] 16. The method according to any one of solutions 1-15, wherein the spatial nearest neighbors in the current PC sample and the nearest neighbors in the reference PC sample are jointly considered for joint spatial-temporal prediction, or wherein the weights used for interpolation depend on factors including temporal distance or spatial distance, or wherein the weights are fixed or explicitly sent to the decoder.

[0249] 17. The method according to any one of solutions 1-16, wherein signal transmission is used from encoder to decoder in bitstream / frame / slice / strip / octree / etc.

[0250] 18. The method according to any one of solutions 1-17, wherein encoding / decoding information is used that depends on dimensions, color format, color components, or slice / picture type.

[0251] 19. An apparatus for processing video data, 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 solutions 1-18.

[0252] 20. A non-transitory computer-readable medium comprising a computer program product for use by a video codec device, the computer program product comprising computer-executable instructions stored on the non-transitory computer-readable medium such that, when executed by a processor, the video codec device performs the method according to any one of solutions 1-18.

[0253] 21. A non-transitory computer-readable recording medium storing a bitstream of video generated by a method performed by a video processing apparatus, wherein the method includes: transmitting data based on a reference node (DC). ref DC of the current node (DC) cur The DC and one or more thresholds are used to disable AC inter-frame prediction, determine the application of Region Adaptive Hierarchical Transform (RAHT) in geometry-based point cloud compression (G-PCC), and generate a bitstream based on the determination.

[0254] 22. A method for storing a video bitstream, comprising: via a reference node (DC) ref DC of the current node (DC) cur The method involves disabling AC inter-frame prediction using DC and one or more thresholds, determining the application of Region Adaptive Hierarchical Transform (RAHT) in geometry-based point cloud compression (G-PCC), generating a bitstream based on the determination, and storing the bitstream in a non-transitory computer-readable recording medium.

[0255] 23. A method, apparatus or system described in this disclosure.

[0256] A further list of example solutions is provided below.

[0257] 1. A method for processing media data, comprising: when utilizing Region Adaptive Hierarchical Transformation (RAHT) in Geometry-Based Point Cloud Compression (G-PCC), based on a reference node (DC) ref DC of the current node (DC) cur The DC and one or more thresholds are used to determine whether AC inter-frame prediction is disabled; and when AC inter-frame prediction is disabled, the conversion between visual media data and bitstream is performed.

[0258] 2. The method according to Solution 1 further includes disabling AC inter-frame prediction when the following conditions are met:

[0259]

[0260] Where Th1 is the first threshold among one or more thresholds, and Th2 is the second threshold among one or more thresholds.

[0261] 3. The method according to any one of solutions 1-2, wherein when performing AC inter-frame prediction in the transform domain, DC ref In the RAHT transform domain.

[0262] 4. The method described in Solution 2 further includes a replacement condition based on the attribute value of the parent node of the current node and the attribute value of the parent node of the reference node.

[0263] 5. The method described in Solution 4 further includes replacing the DC with the sum of the attribute values ​​of the current node's parent nodes. cur And replace the DC with the sum of the attribute values ​​of the parent node of the reference node. ref .

[0264] 6. The method described in Solution 4 further includes replacing the DC with the average of the attribute values ​​of the current node's parent node. cur And replace the DC with the average attribute value of the parent node of the reference node. ref .

[0265] 7. The method according to any one of solutions 1-6, wherein DC ref It is derived from one or more nodes in a reference point cloud (PC) sample.

[0266] 8. The method according to any one of solutions 1-6, wherein the sum of attribute values ​​of the parent nodes of the reference node is derived from one or more nodes in the reference point cloud (PC) sample.

[0267] 9. The method according to any one of solutions 1-6, wherein the average attribute value of the parent node of the reference node is derived from one or more nodes in the reference point cloud (PC) sample.

[0268] 10. The method according to any one of solutions 1-6, wherein DC ref It is derived from the corresponding nodes in the reference point cloud (PC) sample.

[0269] 11. The method according to any one of solutions 1-6, wherein DC ref It is derived from the corresponding nodes after motion compensation.

[0270] 12. The method according to any one of solutions 1-6, wherein DC ref It is derived by interpolating at the location in the reference point cloud (PC) sample.

[0271] 13. The method according to Solution 2, wherein the first threshold (Th1) and the second threshold (Th2) are fixed at the encoder and the decoder.

[0272] 14. The method according to Solution 2, wherein the first threshold (Th1) and the second threshold (Th2) are transmitted to the decoder.

[0273] 15. The method according to Solution 1, wherein one or more thresholds are different for at least one of different sequences and different frames.

[0274] 16. The method described in Solution 1, wherein one or more thresholds are different for different attribute channels.

[0275] 17. The method according to Solution 1, wherein one or more thresholds are different for different regions and at least one of different RAHT layers.

[0276] 18. The method according to Solution 1, wherein one or more thresholds depend on one or more factors including quantization parameters and global motion.

[0277] 19. The method according to Solution 1 further includes disabling AC inter-frame prediction when the following conditions are met:

[0278] Where Th1 is the first threshold among one or more thresholds, and Th2 is the second threshold among one or more thresholds.

[0279] 20. The method according to Solution 1 further includes: when there is no reference node at the motion compensation location, using interpolation techniques in the reference frame for AC inter-frame prediction.

[0280] 21. The method according to solution 20, wherein the interpolation technique includes nearest neighbor interpolation.

[0281] 22. The method according to solution 21, wherein the nearest neighbor interpolation is based on Euclidean distance.

[0282] 23. The method according to solution 21, wherein the nearest neighbor interpolation is based on the nearest Morton code.

[0283] 24. The method according to solution 20, wherein the interpolation technique depends on DC. cur .

[0284] 25. The method according to solution 24 further includes performing a search in a reference point cloud (PC) sample to determine the closest DC. cur The nodes of the DC.

[0285] 26. The method according to solution 24 further includes, but is based on spatial distance and DC cur With DC ref The difference between the two spatial domains is used to determine the optimal reference node, wherein the spatial difference includes Euclidean distance or Morton code distance.

[0286] 27. The method according to solution 20, wherein the interpolation technique includes interpolation at a reference node, and wherein the interpolation at the reference node is based on multiple nearest neighbors.

[0287] 28. The method according to solution 27, wherein each of the plurality of nearest neighbors is weighted based on its distance from the interpolation point.

[0288] 29. The method according to solution 27, wherein the number of the plurality of nearest neighbors is fixed.

[0289] 30. The method according to solution 27, wherein the number of the plurality of nearest neighbors is based on at least one of the RAHT layer and the attribute channel.

[0290] 31. According to the method of solution 27, one or more of the maximum number of the plurality of nearest neighbors and the minimum number of the plurality of nearest neighbors are transmitted to the decoder.

[0291] 32. The method according to solution 20 further includes determining, based on eligibility criteria, that one or more of the plurality of nearest neighbors are unsuitable for the interpolation technique, and disabling the use of the one or more nearest neighbors determined to be unsuitable.

[0292] 33. The method according to solution 20 further includes using the interpolation results to generate inter-frame predictions.

[0293] 34. The method according to Solution 20 further includes deriving the AC inter-frame prediction based on the interpolation technique, and then combining the AC inter-frame prediction with the intra-frame prediction to obtain the final prediction.

[0294] 35. The method according to solution 34, wherein the final prediction includes the average of the AC inter-frame prediction and the intra-frame prediction.

[0295] 36. The method according to solution 34, wherein the final prediction comprises a weighted average of the AC inter-frame prediction and the intra-frame prediction, and wherein the weights for different layers are predetermined or transmitted to the decoder.

[0296] 37. The method according to Solution 20 further includes determining the spatial-temporal prediction based on the spatial nearest neighbors in the current point cloud (PC) sample and the nearest neighbors in the reference PC sample.

[0297] 38. The method according to solution 37, wherein the weights used for interpolation are based on a factor including at least one of temporal distance and spatial distance.

[0298] 39. The method according to solution 37, wherein the weights used for interpolation are fixed or transmitted to the decoder.

[0299] 40. The method according to any one of solutions 1-39, wherein whether and / or how any of the disclosed methods is applied is in the transmission of signals from the encoder to the decoder in at least one of a bitstream, frame, slice, strip, or octree.

[0300] 41. The method according to any one of solutions 1-40, wherein whether and / or how any of the disclosed methods is applied is based on encoding / decoding information including one or more of dimension, color format, color components, slice type and picture type.

[0301] 42. The method according to any one of solutions 1-41, wherein the conversion includes encoding the media data into a bitstream.

[0302] 43. The method according to any one of solutions 1-41, wherein the conversion includes decoding the media data from the bitstream.

[0303] 44. An apparatus for processing video data, 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 solutions 1-43.

[0304] 45. A non-transitory computer-readable medium comprising a computer program product for use by a video codec apparatus, the computer program product comprising computer-executable instructions stored on the non-transitory computer-readable medium such that, when executed by a processor, the video codec apparatus performs the method according to any one of solutions 1-43.

[0305] 46. ​​A non-transitory computer-readable recording medium storing a bitstream of video generated by a method performed by a video processing apparatus, wherein the method includes: when utilizing a region adaptive hierarchical transformation (RAHT) in geometry-based point cloud compression (G-PCC), based on a reference node (DC) ref DC of the current node (DC) cur The DC and one or more thresholds are used to determine whether AC inter-frame prediction is disabled; and the bitstream is generated with AC inter-frame prediction disabled.

[0306] 47. A method for storing a bitstream of video, comprising: when utilizing Region Adaptive Hierarchical Transform (RAHT) in Geometry-Based Point Cloud Compression (G-PCC), based on a reference node (DC) ref DC of the current node (DC) cur The method determines whether to disable AC inter-frame prediction by using DC and one or more thresholds; generates the bitstream with AC inter-frame prediction disabled; and stores the bitstream in a non-transitory computer-readable recording medium.

[0307] 48. A method, apparatus or system described in this disclosure.

[0308] In the described solution, the encoder conforms to the format rules by generating a codec representation based on those rules. In the described solution, the decoder parses the syntax elements in the codec representation using known information about their presence or absence, based on the format rules, to produce the decoded video.

[0309] In this disclosure, the term "video processing" can refer to video encoding, video decoding, video compression, or video decompression. For example, a video compression algorithm can be applied during the conversion from a pixel representation of a video to a corresponding bitstream representation, and vice versa. For example, the bitstream representation of the current video block can correspond to bits at co-positions or propagated at different positions in the bitstream defined by the syntax. For example, a macroblock can be encoded based on the error residual value after transformation and encoding / decoding, and also using bits from the header and other fields in the bitstream. Furthermore, during the conversion, the decoder can, based on this determination, parse the bitstream knowing whether some fields may or may not be present, as described in the solutions above. Similarly, the encoder can determine whether to include or exclude specific syntax fields and generate the codec representation accordingly by including or excluding syntax fields from the codec representation.

[0310] The disclosed and other solutions, examples, embodiments, modules, and functional operations described herein can be implemented in digital electronic circuits, or in computer software, firmware, or hardware, including the structures disclosed herein and their structural equivalents, or in combinations thereof. The disclosed embodiments and other embodiments can be implemented as one or more computer program products, i.e., one or more computer program instruction modules encoded on a computer-readable medium for execution by a data processing apparatus or for controlling the operation of a data processing apparatus. The computer-readable medium can be a machine-readable storage device, a machine-readable storage substrate, a storage device, a material composition affecting machine-readable propagation signals, or a combination thereof. The term "data processing apparatus" includes all means, devices, and machines for processing data, including, for example, a programmable processor, a computer, or multiple processors or computers. In addition to hardware, the apparatus may also include code that creates an execution environment for an associated computer program, such as code constituting processor firmware, a protocol stack, a database management system, an operating system, or a combination thereof. Propagation signals are artificially generated signals, such as machine-generated electrical signals, optical signals, or electromagnetic signals, which are generated to encode information to be transmitted to a suitable receiver device.

[0311] Computer programs (also known as programs, software, software applications, scripts, or code) can be written in any programming language, including compiled or interpreted languages, and can be deployed in any form, including standalone programs or modules, components, subroutines, or other units suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the related program, or in multiple co-located files (e.g., a file storing one or more modules, subroutines, or code portions). A computer program can be deployed to execute on one computer or on multiple computers located at a single site or distributed across multiple sites and interconnected by a communications network.

[0312] The processing and logic flows described in this disclosure can be executed by one or more programmable processors that execute one or more computer programs to perform functions by manipulating input data and generating outputs. The processing and logic flows can also be executed by special-purpose logic circuitry, and the apparatus can be implemented as special-purpose logic circuitry, such as field-programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs).

[0313] Processors suitable for executing computer programs include, for example, general-purpose and special-purpose microprocessors, and any one or more processors of any type of digital computer. Typically, a processor receives instructions and data from read-only memory or random access memory, or both. The basic components of a computer are a processor that executes instructions and one or more storage devices that store the instructions and data. Typically, a computer will also include one or more mass storage devices for storing data, such as magnetic disks, magneto-optical disks, or optical disks, or receive data from or transfer data to one or more mass storage devices via operative coupling, or both. However, a computer does not necessarily have such devices. Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and storage devices, including, for example, semiconductor storage devices such as EPROM, EEPROM, and flash memory devices; magnetic disks, such as internal hard disks or removable hard disks; magneto-optical disks; and CD-ROMs and DVD-ROMs. Processors and memory may be supplemented by or incorporated into special-purpose logic circuitry.

[0314] While this disclosure contains numerous details, these details should not be construed as limiting any subject matter or the scope of the claims, but rather as descriptions of features specific to particular embodiments of a particular art. Certain features described in the context of individual embodiments in this disclosure may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented separately in multiple embodiments, or in any suitable sub-combination. Furthermore, although features may function in certain combinations as described above, and even were originally claimed in this manner, in some cases one or more features in the claimed combination may be removed from that combination, and the claimed combination may be for sub-combinations or variations thereof.

[0315] Similarly, although operations are depicted in a specific order in the accompanying drawings, this should not be construed as requiring such operations to be performed sequentially in the particular order or sequence shown, or requiring all shown operations to be performed in order to achieve the desired result. Furthermore, the partitioning of various system components in the embodiments described in this disclosure should not be construed as requiring such partitioning in all embodiments.

[0316] Only a few implementations and examples are described, and other implementations, improvements and variations may be made based on what is described and shown in this disclosure.

[0317] When there is no intermediary component (other than a line, trace, or other medium between the first and second components), the first component is directly coupled to the second component. When there is an intermediary component between the first and second components other than a line, trace, or other medium, the first component is indirectly coupled to the second component. The term "coupled" and its variations include direct coupling and indirect coupling. The use of the term "about" means including a range of ±10% of the following figures, unless otherwise specified.

[0318] While several embodiments have been provided in this disclosure, it should be understood that the disclosed systems and methods may be embodied in many other specific forms without departing from the spirit or scope of this disclosure. The present examples are to be considered illustrative rather than restrictive and are not intended to limit them to the details set forth herein. For example, various elements or components may be combined or integrated into another system, or certain features may be omitted or not implemented.

[0319] Furthermore, the technologies, systems, subsystems, and methods described and illustrated as discrete or separate in the various embodiments can be combined or integrated with other systems, modules, technologies, or methods without departing from the scope of this disclosure. Other items shown or discussed as couplings can be directly connected or indirectly coupled or communicated through some interface, device, or intermediate component, whether electrical, mechanical, or otherwise. Examples of other changes, substitutions, and modifications that can be determined by those skilled in the art can be made without departing from the spirit and scope of this disclosure.

Claims

1. A method for processing media data, comprising: When utilizing Region Adaptive Hierarchical Transformation (RAHT) in Geometry-Based Point Cloud Compression (G-PCC), based on the reference node (DC) ref DC of the current node (DC) cur The DC and one or more thresholds determine whether AC inter-frame prediction is disabled; as well as Perform the conversion between visual media data and bitstream with the AC inter-frame prediction disabled.

2. The method of claim 1, further comprising: The AC inter-frame prediction is disabled when the following conditions are met: Wherein, Th1 is the first threshold among the one or more thresholds, and Th2 is the second threshold among the one or more thresholds.

3. The method according to any one of claims 1-2, wherein, When performing the AC inter-frame prediction in the transform domain, the DC ref It lies in the RAHT transform domain.

4. The method of claim 2, further comprising: Replace the condition based on the attribute values ​​of the current node's parent node and the attribute values ​​of the reference node's parent node.

5. The method of claim 4, further comprising: Replace the DC with the sum of the attribute values ​​of the parent node of the current node. cur And replace the DC with the sum of the attribute values ​​of the parent node of the reference node. ref .

6. The method of claim 4, further comprising: Replace the DC with the average of the attribute values ​​of the parent node of the current node. cur And replace the DC with the average of the attribute values ​​of the parent node of the reference node. ref .

7. The method according to any one of claims 1-6, wherein, The DC ref It is derived from one or more nodes in a reference point cloud (PC) sample.

8. The method according to any one of claims 1-6, wherein, The sum of the attribute values ​​of the parent node of the reference node is derived from one or more nodes in the reference point cloud (PC) sample.

9. The method according to any one of claims 1-6, wherein, The average value of the attribute value of the parent node of the reference node is derived from one or more nodes in the reference point cloud (PC) sample.

10. The method according to any one of claims 1-6, wherein, The DC ref It is derived from the corresponding nodes in the reference point cloud (PC) sample.

11. The method according to any one of claims 1-6, wherein, The DC ref It is derived from the corresponding nodes after motion compensation.

12. The method according to any one of claims 1-6, wherein, The DC ref It is derived by interpolating at the location in the reference point cloud (PC) sample.

13. The method of claim 2, wherein, The first threshold (Th1) and the second threshold (Th2) are fixed at the encoder and decoder, respectively.

14. The method of claim 2, wherein, The first threshold (Th1) and the second threshold (Th2) are transmitted to the decoder.

15. The method of claim 1, wherein, The thresholds are different for at least one of different sequences and different frames.

16. The method of claim 1, wherein, The thresholds are different for different attribute channels.

17. The method of claim 1, wherein, The thresholds are different for different regions and at least one of different RAHT layers.

18. The method of claim 1, wherein, The one or more thresholds depend on one or more factors, including quantization parameters and global motion.

19. The method of claim 1, further comprising: The AC inter-frame prediction is disabled when the following conditions are met: Wherein, Th1 is the first threshold among the one or more thresholds, and Th2 is the second threshold among the one or more thresholds.

20. The method of claim 1, further comprising: When there is no reference node at the motion compensation location, interpolation techniques are used in the reference frame for the AC inter-frame prediction.

21. The method of claim 20, wherein, The interpolation technique includes nearest neighbor interpolation.

22. The method of claim 21, wherein, The nearest neighbor interpolation is based on Euclidean distance.

23. The method of claim 21, wherein, The nearest neighbor interpolation is based on the nearest Morton code.

24. The method of claim 20, wherein, The interpolation technique depends on the DC. cur .

25. The method of claim 24, further comprising: Perform a search within the reference point cloud (PC) sample to determine the closest point to the DC. cur The nodes of the DC.

26. The method of claim 24, further comprising: Based on spatial distance and the DC cur With the DC ref The difference between the two points determines the optimal reference node, wherein the spatial difference includes Euclidean distance or Morton code distance.

27. The method of claim 20, wherein, The interpolation technique includes interpolation at a reference node, wherein the interpolation at the reference node is based on multiple nearest neighbors.

28. The method of claim 27, wherein, Each of the plurality of nearest neighbors is weighted based on the distance between the nearest neighbor and the interpolation point.

29. The method of claim 27, wherein, The number of the plurality of nearest neighbors is fixed.

30. The method of claim 27, wherein, The number of the multiple nearest neighbors is based on at least one of the RAHT layer and the attribute channel.

31. The method of claim 27, wherein, One or more of the maximum number of the plurality of nearest neighbors and the minimum number of the plurality of nearest neighbors are transmitted to the decoder.

32. The method of claim 20, further comprising: Based on the qualification criteria, one or more of the plurality of nearest neighbors are determined to be unsuitable for the interpolation technique, and one or more of the plurality of nearest neighbors determined to be unsuitable are disabled.

33. The method of claim 20, further comprising: Use the interpolation results to generate inter-frame predictions.

34. The method of claim 20, further comprising: The AC inter-frame prediction is derived based on the interpolation technique, and the AC inter-frame prediction is combined with the intra-frame prediction to obtain the final prediction.

35. The method of claim 34, wherein, The final prediction includes the average of the AC inter-frame prediction and the intra-frame prediction.

36. The method of claim 34, wherein, The final prediction comprises a weighted average of the AC inter-frame prediction and the intra-frame prediction, wherein the weights are predetermined for different layers or transmitted to the decoder.

37. The method of claim 20, further comprising: Spatial-temporal predictions are determined based on the spatial nearest neighbors in the current point cloud (PC) sample and the nearest neighbors in the reference PC sample.

38. The method of claim 37, wherein, The weights used for interpolation are based on factors including at least one of temporal distance and spatial distance.

39. The method of claim 37, wherein, The weights used for interpolation are either fixed or transmitted to the decoder.

40. The method according to any one of claims 1-39, wherein, Whether and / or how any of the disclosed methods are applied is to transmit signals from the encoder to the decoder in at least one of a bitstream, frame, slice, slice, or octree.

41. The method according to any one of claims 1-40, wherein, Whether and / or how any of the disclosed methods are applied is based on encoding / decoding information including one or more of dimension, color format, color components, slice type, and image type.

42. The method according to any one of claims 1-41, wherein, The conversion includes encoding the media data into a bitstream.

43. The method according to any one of claims 1-41, wherein, The conversion includes decoding the media data from the bitstream.

44. An apparatus for processing video data, comprising: processor; And a non-transitory memory having instructions thereon, wherein, when executed by the processor, the instructions cause the processor to perform the method as described in any one of claims 1-43.

45. A non-transitory computer-readable medium comprising a computer program product for use by a video codec apparatus, the computer program product comprising computer-executable instructions stored on the non-transitory computer-readable medium such that, when executed by a processor, the video codec apparatus performs the method as described in any one of claims 1-43.

46. ​​A non-transitory computer-readable recording medium storing a bitstream of video generated by a method performed by a video processing apparatus, wherein, The method includes: When utilizing Region Adaptive Hierarchical Transformation (RAHT) in Geometry-Based Point Cloud Compression (G-PCC), based on the reference node (DC) ref DC of the current node (DC) cur The DC and one or more thresholds are used to determine whether AC inter-frame prediction is disabled; and The bitstream is generated with the AC inter-frame prediction disabled.

47. A method for storing a video bitstream, comprising: When utilizing Region Adaptive Hierarchical Transformation (RAHT) in Geometry-Based Point Cloud Compression (G-PCC), based on the reference node (DC) ref DC of the current node (DC) cur The DC and one or more thresholds are used to determine whether AC inter-frame prediction is disabled; The bitstream is generated with AC inter-frame prediction disabled; and The bit stream is stored in a non-transitory computer-readable recording medium.

48. A method, apparatus or system described in this disclosure.

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