Improved geometric partition modes with intra and inter prediction

Abstract

Encoding information of a coding unit (CU) is received. The CU is partitioned into a first partition and a second partition based on a partition index. The partition index indicates a geometric partition mode (GPM) in which the CU is partitioned into the first partition and the second partition by a straight partition line. Based on a position of the straight partition line within the CU, it is determined whether (i) a first prediction mode of the first partition of the CU is one of an intra mode and an inter mode, and (ii) a second prediction mode of the second partition of the CU is one of an intra mode and an inter mode. The first partition of the CU is reconstructed based on the determined first prediction mode, and the second partition of the CU is reconstructed based on the determined second prediction mode.

Description

[Technical field]

[0001] [Incorporated by reference] This application claims the benefit of priority to U.S. Patent Application No. 17 / 945,040 entitled "IMPROVEMENT ON GEOMETRIC PARTITION MODE WITH INTRA AND INTER PREDICTION," filed September 14, 2022, which claims the benefit of priority to U.S. Provisional Application No. 63 / 252,111 entitled "Geometric Partition Mode with Intra and Inter Prediction," filed October 4, 2021. The entire disclosure of the prior application is incorporated by reference.

[0002] [Technical field] This disclosure describes embodiments generally related to video coding. [Background technology]

[0003] The background discussion provided herein is intended to generally present the context of the present disclosure. Work of the inventors named in this application, to the extent that their work is described in this background section, and aspects of this description that may not otherwise qualify as prior art at the time of filing, are not admitted, either explicitly or implicitly, as prior art to the present disclosure.

[0004] Uncompressed digital video may include a sequence of pictures, each having spatial dimensions of, for example, 1920x1080 luminance samples and associated chrominance samples. The sequence of pictures may have a fixed or variable picture rate (also informally known as frame rate), for example, 60 pictures per second or a picture rate of 60 Hz. Uncompressed video has specific bitrate requirements. For example, 1080p60 4:2:0 video (1920x1080 luminance sample resolution at a frame rate of 60 Hz) with 8 bits per sample requires a bandwidth approaching 1.5 Gbit / s. One hour of such video requires more than 600 Gbytes of storage space.

[0005] One goal of video encoding and decoding may be the reduction of redundancy in the input video signal through compression. Compression may help reduce the aforementioned bandwidth and / or storage space requirements, in some cases by more than one order of magnitude. Both lossless and lossy compression, as well as combinations thereof, may be used. Lossless compression refers to techniques where an exact copy of the original signal can be reconstructed from the compressed original signal. When lossy compression is used, the reconstructed signal may not be identical to the original signal, but the distortion between the original and reconstructed signals is small enough to make the reconstructed signal useful for the intended application. For video, lossy compression is widely used. The amount of acceptable distortion depends on the application, e.g., users of a particular consumer streaming application may tolerate higher distortion than users of a television distribution application. The achievable compression ratio may reflect that a higher tolerable / acceptable distortion can result in a higher compression ratio.

[0006] Video encoders and decoders can utilize techniques from a number of broad categories, including, for example, motion compensation, transform, quantization, and entropy coding.

[0007] Video codec techniques can include a technique known as intra-coding. In intra-coding, sample values ​​are represented without reference to samples or other data from previously reconstructed reference pictures. In some video codecs, a picture is spatially divided into blocks of samples. If all blocks of samples are coded in intra mode, the picture may be an intra picture. Intra pictures and their derivatives, such as independent decoder refresh pictures, can be used to reset the decoder state and thus can be used as the first picture in a coded video bitstream and video session or as a still image. Samples of an intra block can be subjected to a transform, and the transform coefficients can be quantized before entropy coding. Intra prediction can be a technique that minimizes sample values ​​in the pre-transform domain. In some cases, the smaller the DC value and the smaller the AC coefficients after the transform, the fewer bits are needed for a given quantization step size to represent the block after entropy coding.

[0008] Traditional intra-coding, e.g. as known from MPEG-2 generation encoding techniques, does not use intra-prediction. However, some newer video compression techniques include techniques that attempt to do so from surrounding sample data and / or metadata obtained during the encoding and / or decoding of blocks of data that are spatially nearby and preceding in decoding order. Such techniques are referred to below as "intra-prediction" techniques. It should be noted that, at least in some cases, intra-prediction uses only reference data from the current picture being reconstructed, and not from reference pictures.

[0009] There may be various forms of intra prediction. If more than one such technique is available for a given video coding technique, the technique used may be coded in intra prediction mode. In certain cases, a mode may have sub-modes and / or parameters, which may be coded separately or may be included in the mode codeword. Which codeword to use for a given mode, sub-mode and / or parameter combination may affect the coding efficiency gain through intra prediction, as well as the entropy coding technique used to convert the codeword into a bitstream.

[0010] A mode of intra prediction was introduced in H.264, refined in H.265, and further refined in newer coding techniques such as the Joint Exploration Model (JEM), Versatile Video Coding (VVC), and Benchmark Set (BMS). A predictor block can be formed using neighboring sample values ​​belonging to already available samples. The sample values ​​of the neighboring samples are copied to the predictor block according to a certain direction. The reference to the direction used can be coded in the bitstream or it may be predicted itself.

[0011] Referring to FIG. 1A, at the bottom right, a subset of 9 known predictor directions from the 33 possible predictor directions (corresponding to the 33 angle modes of the 35 intra modes) of H.265 is depicted. The point (101) where the arrows converge represents the sample to be predicted. The arrows represent the direction in which the sample is predicted. For example, arrow (102) indicates that sample (101) is predicted from the sample(s) to the top right, at an angle of 45 degrees from the horizontal. Similarly, arrow (103) indicates that sample (101) is predicted from the sample(s) to the bottom left of sample (101), at an angle of 22.5 degrees from the horizontal.

[0012] 1A, at the top left, a square block (104) of 4×4 samples is depicted (indicated by a thick dashed line). The square block (104) contains 16 samples, each labeled with an “S” and its position in the Y dimension (e.g., row index) and its position in the X dimension (e.g., column index). For example, sample S21 is the second sample (from the top) in the Y dimension and the first sample (from the left) in the X dimension. Similarly, sample S44 is the fourth sample in the block (104) in both the Y and X dimensions. Since the block is 4×4 samples in size, S44 is at the bottom right. Additionally, a reference sample is shown that follows a similar numbering scheme. The reference sample is labeled R and its Y position (e.g., row index) and X position (column index) relative to the block (104). In both H.264 and H.265, the predicted samples are neighbors of the block being reconstructed, so there is no need to use negative values.

[0013] Intra-picture prediction can work by copying reference sample values ​​from neighboring samples filled by the signaled prediction direction. For example, assume that the coded video bitstream includes signaling for this block indicating a prediction direction that is consistent with the arrow (102). That is, the sample is predicted from the top right prediction sample or samples at an angle of 45 degrees from the horizontal. Then samples S41, S32, S23, and S14 are predicted from the same reference sample R05. Then sample S44 is predicted from reference sample R08.

[0014] In certain cases, especially when the direction is not divisible by 45 degrees, the values ​​of multiple reference samples may be combined, for example by interpolation, to calculate the reference sample.

[0015] As video coding techniques have developed, the number of possible directions has increased. In H.264 (2003), nine different directions could be represented. This increased to 33 in H.265 (2013), and JEM / VVC / BMS at the time of this disclosure can support up to 65 directions. Experiments are performed to identify the most likely directions, and specific techniques in entropy coding are used to represent those likely directions with a small number of bits while accepting some penalty for less likely directions. Furthermore, the direction itself may be predictable from nearby directions used in nearby already decoded blocks.

[0016] FIG. 1B shows a schematic diagram (110) depicting 65 intra prediction directions with JEM to illustrate the increasing number of prediction directions over time.

[0017] The mapping of intra-prediction direction bits in the coded video bitstream representing the direction can vary from one video coding technique to another, for example from a simple direct mapping of prediction directions to intra-prediction modes to complex adaptation schemes involving codewords, most probable modes, and similar techniques. In any case, however, there may be certain directions that are statistically less likely to occur in the video content than other certain directions. Since the goal of video compression is to reduce redundancy, in a well-performing video coding technique, such less likely ways are represented by a larger number of bits than more probable directions.

[0018] Video encoding and decoding can be performed using inter-picture prediction with motion compensation. Motion compensation can be a lossy compression technique and can refer to a technique in which blocks of sample data from a previously reconstructed picture or part thereof (reference picture) are used for prediction of a newly reconstructed picture or part thereof after being spatially shifted in a direction indicated by a motion vector (hereinafter MV). In some cases, the reference picture can be the same as the picture currently being reconstructed. The MV can have two dimensions, X and Y, or three dimensions, with the third dimension being an indication of the reference picture used (which can indirectly be the temporal dimension).

[0019] In some video compression techniques, the MV applicable to a region of sample data can be predicted from other MVs, e.g., from an MV associated with another region of sample data that is spatially adjacent to the region being reconstructed and precedes it in decoding order. Doing so can significantly reduce the amount of data required to encode the MV, thereby removing redundancy and increasing compression. MV prediction can work effectively because, for example, when encoding an input video signal derived from a camera (known as natural video), there is a statistical probability that regions larger than the region to which a single MV is applicable move in a similar direction and can therefore be predicted, in certain cases, using similar motion vectors derived from the MVs of nearby regions. As a result, the MV found for a given region will be similar or identical to the MV predicted from the surrounding MVs, which, after entropy encoding, can be represented with fewer bits than would be used if encoding the MVs directly. In some cases, MV prediction can be an example of lossless compression of a signal (i.e., an MV) derived from the original signal (i.e., a sample stream). In other cases, the MV prediction itself may be lossy, for example due to rounding errors in computing the predictor from several surrounding MVs.

[0020] Various MV prediction mechanisms are described in H.265 / HEVC (ITU-T Rec. H.265, "High Efficiency Video Coding", December 2016). Among the many MV prediction mechanisms provided by H.265, a technique hereafter referred to as "spatial merge" is described herein.

[0021] Referring to Figure 2, a current block (201) contains samples that the encoder found during the motion search process to be predictable from a previous block of the same size but spatially shifted. Instead of directly encoding its MV, the MV can be derived from metadata associated with one or more reference pictures, for example from the most recent reference picture (in decoding order) using MVs associated with any of the five surrounding samples, denoted A0, A1, and B0, B1, B2 (202-206, respectively). In H.265, MV prediction can use predictors from the same reference picture that neighboring blocks use. Summary of the Invention

[0022] Aspects of this disclosure provide a method and apparatus for video encoding / decoding. In some examples, an apparatus for video decoding includes a processing circuit.

[0023] According to an aspect of the disclosure, a method of video decoding performed in a video decoder is provided. In the method, coding information of a coding unit (CU) of a current picture can be received from a coded video bitstream. The CU can be partitioned into a first partition and a second partition based on a partition index in the coding information. The partition index can indicate a geometric partition mode (GPM) in which the CU is partitioned into a first partition and a second partition by a straight partition line. Based on a position of the straight partition line within the CU, it can be determined whether (i) a first prediction mode of a first partition of the CU is one of an intra mode and an inter mode, and (ii) a second prediction mode of a second partition of the CU is one of an intra mode and an inter mode. The first partition of the CU can be reconstructed based on the determined first prediction mode, and the second partition of the CU can be reconstructed based on the determined second prediction mode.

[0024] In one example, a first prediction mode of a first partition can be determined as an intra mode and a second prediction mode of a second partition can be determined as an inter mode based on the width of the CU being greater than or equal to the height of the CU in response to the straight partition line intersecting the top left corner of the CU.

[0025] In another example, a first prediction mode of a first partition can be determined as an inter mode and a second prediction mode of a second partition can be determined as an intra mode based on the width of the CU being less than the height of the CU in response to the straight partition line intersecting the top left corner of the CU.

[0026] As yet another example, in response to a straight partition line intersecting the upper left corner of the CU, a first prediction mode of the first partition and a second prediction mode of the second partition can be determined based on which of the above reference samples and left reference samples adjacent to the CU are available for intra prediction.

[0027] For example, based on (i) the left reference sample is adjacent to the first partition of the CU and is available for intra prediction, and (ii) the top reference sample is unavailable for intra prediction, a first prediction mode of the first partition can be determined as an intra mode and a second prediction mode of the second partition can be determined as an inter mode.

[0028] In some embodiments, the first prediction mode of the first partition and the second prediction mode of the second partition can be determined based on which of the first partition and the second partition of the CU contains a larger portion of the top corner pixels of the CU.

[0029] In some embodiments, based on the first partition of the CU including a larger portion of the top corner pixels of the CU, a first prediction mode of the first partition can be determined as an intra mode and a second prediction mode of the second partition can be determined as an inter mode.

[0030] In some embodiments, in response to a first portion of an upper corner pixel included in the first partition being equal to a second portion of an upper corner pixel included in the second partition, the first prediction mode and the second prediction mode can be determined based on which of the upper reference sample and the left reference sample is adjacent to one of the first partition and the second partition.

[0031] In some embodiments, whether the first partition of the CU is intra-coded or inter-coded can be determined based on a first index. Whether the second partition of the CU is intra-coded or inter-coded can be determined based on a second index. In response to one of the first partition and the second partition being intra-coded and the other of the first partition and the second partition being inter-coded, an intra mode can be determined from an intra mode list of one of the first partition and the second partition that is intra-coded based on an intra mode index included in the coding information. A merge candidate for the inter mode can be determined from a merge candidate list of the other of the first partition and the second partition that is inter-coded based on a merge index included in the coding information.

[0032] In the method, whether one of the first partition and the second partition of the CU is intra-coded and the other of the first partition and the second partition of the CU is inter-coded can be determined based on a flag included in the coding information. In response to one of the first partition and the second partition of the CU being intra-coded and the other of the first partition and the second partition of the CU being inter-coded, an intra mode can be determined from an intra mode list of one of the first partition and the second partition that is intra-coded based on an intra mode index included in the coding information. A merge candidate for the inter mode can be determined from a merge candidate list of the other of the first partition and the second partition that is inter-coded based on a merge index included in the coding information.

[0033] According to another aspect of the present disclosure, an apparatus is provided, the apparatus including a processing circuit, the processing circuit being configurable to perform any of the methods of video coding.

[0034] Aspects of the present disclosure also provide a non-transitory computer-readable medium having stored thereon instructions that, when executed by a computer, cause the computer to perform a method for video decoding. [Brief description of the drawings]

[0035] Further features, nature and various advantages of the disclosed subject matter will become more apparent from the following detailed description and the accompanying drawings. [Figure 1A] FIG. 2 is a schematic diagram of an example subset of intra-prediction modes. [Figure 1B] FIG. 2 is an illustration of an exemplary intra-prediction direction. [Diagram 2] FIG. 2 is a schematic diagram of a current block and its surrounding spatial merging candidates in one example. [Diagram 3] FIG. 1 is a schematic diagram of a simplified block diagram of a communication system according to an embodiment. [Figure 4] FIG. 4 is a schematic diagram of a simplified block diagram of a communication system (400) according to an embodiment. [Diagram 5] FIG. 2 is a schematic diagram of a simplified block diagram of a decoder according to an embodiment. [Figure 6] FIG. 2 is a schematic diagram of a simplified block diagram of an encoder according to an embodiment. [Figure 7] 4 shows a block diagram of an encoder according to another embodiment; [Figure 8] 4 shows a block diagram of a decoder according to another embodiment; [Figure 9] 13 illustrates exemplary locations of spatial merge candidates according to another embodiment. [Figure 10] 1 illustrates an exemplary redundancy check of spatial merge candidates. [Figure 11] 4 shows a schematic diagram of scaling of motion vectors of temporal merge candidates according to one embodiment; [Figure 12] 1 illustrates exemplary candidate positions for temporal merge candidates according to one embodiment. [Figure 13]1 illustrates an exemplary angular distribution for a geometric partition mode (GPM) according to one embodiment. [Figure 14] 1 illustrates an example partition line for a GPM according to one embodiment. [Figure 15A] 1 illustrates a first exemplary partition of a GPM according to one embodiment. [Figure 15B] 1 illustrates a second exemplary partition of a GPM according to one embodiment. [Figure 15C] 1 illustrates a third exemplary partition of a GPM according to one embodiment. [Figure 16] 1 shows a flowchart outlining an exemplary decoding process according to some embodiments of the present disclosure. [Figure 17] 1 shows a flowchart outlining an exemplary encoding process according to some embodiments of the present disclosure. [Figure 18] FIG. 1 is a schematic diagram of a computer system according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] FIG. 3 illustrates a simplified block diagram of a communication system (300) according to an embodiment of the present disclosure. The communication system (300) includes a plurality of terminal devices that can communicate with each other, for example, via a network (350). For example, the communication system (300) includes a first pair of terminal devices (310) and (320) interconnected via the network (350). In the example of FIG. 3, the first pair of terminal devices (310) and (320) perform a unidirectional transmission of data. For example, the terminal device (310) may encode video data (e.g., a stream of video pictures captured by the terminal device (310)) for transmission to the other terminal device (320) via the network (350). The encoded video data may be transmitted in the form of one or more encoded video bitstreams. The terminal device (320) may receive the encoded video data from the network (350), decode the encoded video data to reconstruct the video pictures, and display the video pictures according to the reconstructed video data. One-way data transmission may be common, such as in media service applications.

[0037] In another example, the communication system (300) includes a second pair of terminal devices (330) and (340) performing bidirectional transmission of encoded video data, such as may occur during a video conference. For the bidirectional transmission of data, in one example, each of the terminal devices (330) and (340) may encode video data (e.g., a stream of video pictures captured by the terminal device) for transmission to the other of the terminal devices (330) and (340) over the network (350). Each of the terminal devices (330) and (340) may receive the encoded video data transmitted by the other of the terminal devices (330) and (340), decode the encoded video data to reconstruct the video pictures, and display the video pictures on an accessible display device in accordance with the reconstructed video data.

[0038] In the example of FIG. 3, the terminal devices (310), (320), (330), and (340) may be depicted as a server, a personal computer, and a smartphone, although the principles of the present disclosure may not be so limited. Embodiments of the present disclosure find application in laptop computers, tablet computers, media players, and / or dedicated video conferencing equipment. The network (350) represents any number of networks that convey encoded video data between the terminal devices (310), (320), (330), and (340), including, for example, wired (wired) and / or wireless communication networks. The communication network (350) may exchange data in circuit-switched and / or packet-switched channels. Exemplary networks include telecommunications networks, local area networks, wide area networks, and / or the Internet. For purposes of discussion herein, the architecture and topology of the network (350) may not be important to the operation of the present disclosure, unless otherwise described below.

[0039] 4 shows an arrangement of a video encoder and a video decoder in a streaming environment as an example of an application for the disclosed subject matter. The disclosed subject matter may be equally applicable to other video-enabled applications including, for example, video conferencing, digital TV, storage of compressed video on digital media including CDs, DVDs, memory sticks, etc.

[0040] The streaming system may include a video source (401), e.g., a digital camera, and may include a capture subsystem (413) that generates, e.g., a stream of uncompressed video pictures (402). In one example, the stream of video pictures (402) includes samples captured by a digital camera. The stream of video pictures (402), depicted as a thick line to emphasize its high data volume compared to the encoded video data (404) (or encoded video bitstream), may be processed by an electronic device (420) that includes a video encoder (403) coupled to the video source (401). The video encoder (403) may include hardware, software, or a combination thereof to enable or implement aspects of the disclosed subject matter, as described in more detail below. The encoded video data (404) (or encoded video bitstream (404)), depicted as a thin line to emphasize its lower data volume compared to the stream of video pictures (402), may be stored in a streaming server (405) for future use. One or more streaming client subsystems, such as the client subsystems (406) and (408) of FIG. 4, can access the streaming server (405) to retrieve copies (407) and (409) of the encoded video data (404). The client subsystem (406) can include a video decoder (410), for example within an electronic device (430). The video decoder (410) decodes an input copy (407) of the encoded video data and generates an output stream (411) of video pictures that can be rendered on a display (412) (e.g., a display screen) or other rendering device (not shown). In some streaming systems, the encoded video data (404), (407), and (409) (e.g., a video bitstream) can be encoded according to a particular video encoding / compression standard. Examples of these standards include ITU-T Recommendation H.265.In one example, the developing video coding standard is informally known as Versatile Video Coding (VVC), and the disclosed subject matter may be used in the context of VVC.

[0041] It is noted that electronic devices 420 and 430 may include other components (not shown). For example, electronic device 420 may include a video decoder (not shown), and electronic device 430 may also include a video encoder (not shown).

[0042] 5 shows a block diagram of a video decoder (510) according to an embodiment of the present disclosure. The video decoder (510) can be included in an electronic device (530). The electronic device (530) can include a receiver (531) (e.g., a receiving circuit). The video decoder (510) can be used in place of the video decoder (310) in the example of FIG. 4.

[0043] The receiver (531) may receive one or more coded video sequences to be decoded by the video decoder (510), one coded video sequence at a time, in the same or another embodiment, and the decoding of each coded video sequence is independent of the other coded video sequences. The coded video sequences may be received from a channel (501), which may be a hardware / software link to a storage device that stores the coded video data. The receiver (531) may receive the coded video data together with other data, such as coded audio data and / or auxiliary data streams, which may be forwarded to respective usage entities (not shown). The receiver (531) may separate the coded video sequences from the other data. To combat network jitter, a buffer memory (515) may be coupled between the receiver (531) and the entropy decoder / parser (520) (hereinafter the "parser"). In certain applications, the buffer memory (515) is part of the video decoder (510). In other applications, it may be external to the video decoder (510) (not shown). In yet other applications, there may be a buffer memory (not shown) external to the video decoder (510), e.g., to combat network jitter, and another buffer memory (515) internal to the video decoder (510), e.g., to handle playback timing. If the receiver (531) is receiving data from a store / forward device of sufficient bandwidth and controllability, or from an isochronous network, the buffer memory (515) may not be required or may be small. For use with best-effort packet networks such as the Internet, the buffer memory (515) may be required and may be relatively large, advantageously of adaptive size, and may be implemented, at least in part, in an operating system or similar element (not shown) external to the video decoder (510).

[0044] The video decoder (510) may include a parser (520) for reconstructing symbols (521) from the coded video sequence. These categories of symbols include information used to manage the operation of the video decoder (510) and potentially information for controlling a rendering device such as a render device (512) (e.g., a display screen). The rendering device may not be an integral part of the electronic device (530) as shown in FIG. 5, but may be coupled to the electronic device (530). The control information for the rendering device(s) may be in the form of Supplementary Enhancement Information (SEI messages) or Video Usability Information (VUI) parameter set fragments (not shown). The parser (520) may parse / entropy decode the received coded video sequence. The coding of the coded video sequence may follow a video coding technique or standard and may follow various principles including variable length coding, Huffman coding, arithmetic coding with or without context sensitivity, etc. The parser (520) can extract from the coded video sequence a set of subgroup parameters for at least one of the subgroups of pixels in the video decoder based on at least one parameter corresponding to the group. The subgroups can include Groups of Pictures (GOPs), pictures, tiles, slices, macroblocks, Coding Units (CUs), blocks, Transform Units (TUs), Prediction Units (PUs), etc. The parser (520) can also extract information from the coded video sequence, such as transform coefficients, quantizer parameter values, motion vectors, etc.

[0045] The parser (520) can perform an entropy decoding / parsing operation on the video sequence received from the buffer memory (515) to generate symbols (521).

[0046] The reconstruction of symbols (521) can involve several different units, depending on the type of coded video picture or portions thereof (e.g., inter and intra pictures, inter and intra blocks) and other factors. Which units are involved and how can be controlled by subgroup control information parsed by the parser (520) from the coded video sequence. The flow of such subgroup control information between the parser (520) and the following units is not depicted for clarity.

[0047] In addition to the functional blocks already mentioned, the video decoder (510) can be conceptually divided into a number of functional units, as described below. In a practical implementation working within commercial constraints, many of these units will interact closely with each other and may be at least partially integrated with each other. However, for purposes of describing the disclosed subject matter, the following conceptual subdivision into functional units is appropriate.

[0048] The first unit is a scalar / inverse transform unit (551). The scalar / inverse transform unit (551) receives quantized transform coefficients and control information as symbol(s) (521) from the parser (520). The control information includes which transform to use, block size, quantization factor, quantization scaling matrix, etc. The scalar / inverse transform unit (551) can output blocks containing sample values ​​that can be input to an aggregator (555).

[0049] In some cases, the output samples of the scaler / inverse transform (551) may relate to intra-coded blocks, i.e., blocks that do not use prediction information from a previously reconstructed picture, but may use prediction information from a previously reconstructed portion of the current picture. Such prediction information may be provided by an intra-picture prediction unit (552). In some cases, the intra-picture prediction unit (552) generates a block of the same size and shape as the block being reconstructed using surrounding already reconstructed information taken from a current picture buffer (558). The current picture buffer (558) may, for example, buffer a partially reconstructed current picture and / or a fully reconstructed current picture. The aggregator (555) may add, on a sample-by-sample basis, the prediction information generated by the intra-prediction unit (552) to the output sample information provided by the scaler / inverse transform unit (551).

[0050] In other cases, the output samples of the scalar / inverse transform unit (551) may relate to an inter-coded, potentially motion-compensated block. In such cases, the motion compensation prediction unit (553) may access a reference picture memory (557) to fetch samples used for prediction. After motion compensating the fetched samples according to the symbols (521) for the block, these samples may be added by an aggregator (555) to the output of the scalar / inverse transform unit (in this case referred to as residual samples or residual signals) to generate output sample information. The addresses in the reference picture memory (557) from which the motion compensation unit (553) fetches prediction samples may be controlled by motion vectors available to the motion compensation unit (553) in the form of symbols (521). The symbols may have, for example, X, Y, and reference picture components. Motion compensation may include interpolation of sample values ​​fetched from the reference picture memory (557) when subsample accurate motion vectors are used, motion vector prediction mechanisms, and the like.

[0051] The output samples of the aggregator (555) may be subjected to various loop filtering techniques in a loop filter unit (556). Video compression techniques may include in-loop filter techniques that are controlled by parameters contained in the coded video sequence (also called the coded video bitstream) and made available to the loop filter unit (556) as symbols (521) from the parser (520), but may also be responsive to meta-information obtained during decoding of previous portions (in decoding order) of the coded picture or coded video sequence, as well as to previously reconstructed loop filtered sample values.

[0052] The output of the loop filter unit (556) can be a sample stream, which can be output to a render device (512) or stored in a reference picture memory (557) for use in future inter-picture prediction.

[0053] Once a coded picture is fully reconstructed, it can be used as a reference picture for future prediction. For example, once a coded picture corresponding to a current picture is fully reconstructed and the coded picture is identified as a reference picture (e.g., by the parser (520)), the current picture buffer (558) can become part of the reference picture memory (557), and a fresh current picture buffer can be reallocated before starting the reconstruction of a subsequent coded picture.

[0054] The video decoder (510) may perform decoding operations according to a given video compression technique in a standard such as ITU-T Recommendation H.265. The encoded video sequence may be compliant with the syntax prescribed by the video compression technique or standard being used, in the sense that the encoded video sequence follows the syntax of the video compression technique or standard and a profile documented in the video compression technique or standard. In particular, a profile may select a particular tool from all tools available in the video compression technique or standard as the only tool available for use under that profile. Compliance may also require that the complexity of the encoded video sequence be within a range defined by a level of the video compression technique or standard. In some cases, the level constrains the maximum picture size, maximum frame rate, maximum reconstruction sample rate (e.g., measured in units of megasamples per second), maximum reference picture size, etc. The limits set by the level may be further constrained through a Hypothetical Reference Decoder (HRD) specification and metadata for HRD buffer management, possibly signaled in the encoded video sequence.

[0055] In some embodiments, the receiver (531) may receive additional (redundant) data along with the encoded video. The additional data may be included as part of the encoded video sequence(s). The additional data may be used by the video decoder (510) to properly decode the data and / or to more accurately reconstruct the original video data. The additional data may be in the form of, for example, temporal, spatial, or signal-to-noise ratio (SNR) enhancement layers, redundant slices, redundant pictures, forward error correction codes, etc.

[0056] 6 shows a block diagram of a video encoder (603) according to an embodiment of the present disclosure. The video encoder (603) is included in an electronic device (620). The electronic device (620) includes a transmitter (640) (e.g., a transmission circuit). The video encoder (603) can be used in place of the video encoder (403) in the example of FIG. 4.

[0057] The video encoder (603) can receive video samples from a video source (601) (which is not part of the electronic device (620) in the example of FIG. 6) that can capture video images to be encoded by the video encoder (603). In another example, the video source (601) is part of the electronic device (620).

[0058] The video source (601) may provide a source video sequence to be encoded by the video encoder (603) in the form of a digital video sample stream that may be of any suitable bit depth (e.g., 8-bit, 10-bit, 12-bit, ...), any color space (e.g., BT.601 YCrCB, RGB, ...) and any suitable sampling structure (e.g., YCrCb 4:2:0, YCrCb 4:4:4). In a media service system, the video source (601) may be a storage device that stores pre-prepared video. In a video conferencing system, the video source (601) may be a camera that captures image information locally as a video sequence. The video data may be provided as a number of individual pictures that impart motion when viewed in sequence. The pictures themselves may be organized as a spatial array of pixels, each of which may contain one or more samples, depending on the sampling structure, color space, etc., in use. Those skilled in the art can easily understand the relationship between pixels and samples. The following description focuses on samples.

[0059] According to an embodiment, the video encoder (603) can encode and compress pictures of a source video sequence into an encoded video sequence (643) in real-time or under any other time constraint required by an application. Enforcing an appropriate encoding rate is one function of the controller (650). In some embodiments, the controller (650) controls and is operatively coupled to other functional units, such as those described below. Such couplings are not depicted for clarity. Parameters set by the controller (650) can include parameters related to rate control (picture skip, quantizer, lambda value for rate-distortion optimization techniques, ...), picture size, group of pictures (GOP) layout, maximum motion vector search range, etc. The controller (650) can be configured to have other suitable functions for the video encoder (603) optimized for a particular system design.

[0060] In some embodiments, the video encoder (603) is configured to operate in an encoding loop. As a simplistic description, in one example, the encoding loop can include a source encoder (630) (e.g., responsible for generating symbols, such as a symbol stream, based on an input picture to be encoded and a reference picture(s)) and a (local) decoder (633) embedded in the video encoder (603). The decoder (633) reconstructs the symbols to generate sample data in a similar manner that a (remote) decoder would also generate (in the video compression techniques considered in the disclosed subject matter, any compression between the symbols and the encoded video bitstream is lossless). The reconstructed sample stream (sample data) is input to a reference picture memory (634). Since the decoding of the symbol stream produces bit-accurate results regardless of the decoder location (local or remote), the contents of the reference picture memory (634) are also bit-accurate between the local and remote encoders. In other words, the predictor of the encoder "sees" exactly the same sample values ​​as the reference picture samples that the decoder "sees" when using the prediction during decoding. This basic principle of reference picture synchrony (and the resulting drift when synchrony cannot be maintained, e.g., due to channel errors) is also used in several related technologies.

[0061] The operation of the "local" decoder (633) may be the same as the operation of a "remote" decoder, e.g., the video decoder (410), already described in detail above in connection with Figure 5. However, referring also briefly to Figure 5, because symbols are available and the encoding / decoding of the symbols into a coded video sequence by the entropy coder (645) and parser (420) may be lossless, the entropy decoding portion of the video decoder (410), including the buffer memory (415) and the parser (420), may not be fully implemented in the local decoder (633).

[0062] An observation that can be made at this point is that any decoder technique, other than parsing / entropy decoding, that exists in the decoder must exist in substantially the same functional form in the corresponding encoder. For this reason, the disclosed subject matter focuses on the decoder operation. A description of the encoder techniques can be omitted, since they are the inverse of the decoder techniques that are described generically. Only in certain areas is more detailed explanation necessary, and is provided below.

[0063] During operation, in some examples, the source encoder (630) may perform motion-compensated predictive encoding, which predictively encodes an input picture with reference to one or more previously encoded pictures from a video sequence, designated as “reference pictures.” In this manner, the encoding engine (632) encodes differences between pixel blocks of the input picture and pixel blocks of a reference picture(s) that may be selected as predictive references for the input picture.

[0064] The local video decoder (633) can decode the encoded video data of pictures that may be designated as reference pictures based on the symbols generated by the source encoder (630). The operation of the encoding engine (632) can advantageously be a lossy process. When the encoded video data can be decoded in a video decoder (not shown in FIG. 6), the reconstructed video sequence can be a copy of the source video sequence, typically with some errors. The local video decoder (633) can replicate the decoding process that may be performed on the reference pictures by the video decoder and store the reconstructed reference pictures in a reference picture cache (634). In this way, the video encoder (603) can locally store copies of reconstructed reference pictures that have common content (in the absence of transmission errors) as the reconstructed reference pictures that would be obtained by the far-end video decoder.

[0065] The predictor (635) may perform a prediction search for the coding engine (632). That is, for a new picture to be coded, the predictor (635) may search the reference picture memory (634) for sample data (as candidate reference pixel blocks) or specific metadata, such as reference picture motion vectors, block shapes, etc., that may serve as suitable prediction references for the new picture. The predictor (635) may operate on a sample block-by-pixel block basis to find suitable prediction references. In some cases, as determined by the search results obtained by the predictor (635), the input picture may have prediction references drawn from multiple reference pictures stored in the reference picture memory (634).

[0066] The controller (650) may manage the encoding operations of the source encoder (630), including, for example, setting the parameters and subgroup parameters used to encode the video data.

[0067] The output of all of the above functional units may undergo entropy coding in an entropy coder (645), which converts the symbols produced by the various functional units into a coded video sequence by losslessly compressing the symbols according to techniques such as Huffman coding, variable length coding, arithmetic coding, etc.

[0068] The transmitter (640) can buffer the encoded video sequence generated by the entropy encoder (645) and prepare it for transmission over a communication channel (660), which may be a hardware / software link to a storage device that stores the encoded video data. The transmitter (640) can merge the encoded video data from the video encoder (630) with other data to be transmitted, such as encoded audio data and / or auxiliary data streams (sources not shown).

[0069] The controller (650) may manage the operation of the video encoder (603). During encoding, the controller (650) may assign a certain coding picture type to each coded picture. The coding picture type may affect the coding technique that may be applied to each picture. For example, pictures may often be assigned as one of the following picture types:

[0070] An intra picture (I-picture) may be one that can be coded and decoded without using other pictures in a sequence as a source of prediction. Some video codecs allow different types of intra pictures, including, for example, Independent Decoder Refresh ("IDR") pictures. Those skilled in the art will recognize these variations of I-pictures and their respective uses and characteristics.

[0071] A predictive picture (P-picture) may be one that can be encoded and decoded using intra- or inter-prediction, which uses at most one motion vector and reference index to predict the sample values ​​of each block.

[0072] Bidirectionally predicted pictures (B-pictures) may be those that can be coded and decoded using intra- or inter-prediction, which uses up to two motion vectors and reference indices to predict the sample values ​​of each block. Similarly, multi-predictive pictures can use more than two reference pictures and associated metadata for the reconstruction of a single block.

[0073] A source picture is usually spatially divided into multiple sample blocks (e.g., blocks of 4x4, 8x8, 4x8, or 16x16 samples each) and may be coded block by block. Blocks may be predictively coded with reference to other (already coded) blocks, as determined by the coding assignment applied to the respective picture of the block. For example, blocks of an I-picture may be non-predictively coded or may be predictively coded with reference to already coded blocks of the same picture (spatial or intra prediction). Pixel blocks of a P-picture may be predictively coded via spatial prediction or via temporal prediction with reference to one previously coded reference picture. Blocks of a B-picture may be predictively coded via spatial prediction or via temporal prediction with reference to one or two previously coded reference pictures.

[0074] The video encoder (603) may perform encoding operations according to a given video encoding technique or standard, such as ITU-T Recommendation H.265. In its operations, the video encoder (603) may perform various compression operations, including predictive encoding operations that exploit temporal and spatial redundancy in the input video sequence. Thus, the encoded video data may conform to a syntax specified by the video encoding technique or standard used.

[0075] In some embodiments, the transmitter (640) may transmit additional data along with the encoded video. The source encoder (630) may include such data as part of the encoded video sequence. The additional data may include temporal / spatial / SNR enhancement layers, other forms of redundant data such as redundant pictures and slices, SEI messages, VUI parameter set fragments, etc.

[0076] A video may be captured as multiple source pictures (video pictures) in a temporal sequence. Intra-picture prediction (often abbreviated as intra-prediction) exploits spatial correlation in a given picture, while inter-picture prediction exploits correlation (temporal or other) between pictures. In one example, a particular picture to be coded / decoded, called a current picture, is divided into blocks. If a block in the current picture is similar to a reference block in a previously coded and still buffered reference picture in the video, that block in the current picture can be coded by a vector called a motion vector. A motion vector points to a reference block in a reference picture, and may have a third dimension that identifies the reference picture if multiple reference pictures are used.

[0077] In some embodiments, bi-prediction techniques can be used in inter-picture prediction. According to bi-prediction techniques, two reference pictures are used, such as a first reference picture and a second reference picture, both of which precede the current picture in decoding order (but may also be past and future, respectively, in display order) in the video. A block in the current picture can be coded by a first motion vector that points to a first reference block in the first reference picture and a second motion vector that points to a second reference block in the second reference picture. A block can be predicted by a combination of the first and second reference blocks.

[0078] Furthermore, to improve coding efficiency, merge mode techniques can be used in inter-picture prediction.

[0079] According to some embodiments of the present disclosure, predictions such as inter-picture prediction and intra-picture prediction are performed on a block-by-block basis. For example, according to the HEVC standard, pictures in a sequence of video pictures are divided into coding tree units (CTUs) for compression, and the CTUs in a picture have the same size, such as 64×64 pixels, 32×32 pixels, or 16×16 pixels. In general, a CTU includes three coding tree blocks (CTBs), one luma CTB and two chroma CTBs. Each CTU can be recursively quadtree partitioned into one or more coding units (CUs). For example, a CTU of 64×64 pixels can be partitioned into one CU of 64×64 pixels, or four CUs of 32×32 pixels, or 16 CUs of 16×16 pixels. In one example, each CU is analyzed to determine a prediction type for that CU, such as an inter prediction type or an intra prediction type. A CU is divided into one or more prediction units (PUs) depending on temporal and / or spatial predictability. In general, each PU includes a luma prediction block (PB) and two chroma PBs. In an embodiment, prediction operations in coding (encoding / decoding) are performed in units of prediction blocks. Taking a luma prediction block as an example of a prediction block, the prediction block includes a matrix of values ​​(e.g., luma values) for pixels, such as 8×8 pixels, 16×16 pixels, 8×16 pixels, 16×8 pixels, etc.

[0080] 7 shows a diagram of a video encoder (703) according to another embodiment of the present disclosure. The video encoder (703) is configured to receive a processed block (e.g., a predictive block) of sample values ​​in a current video picture in a sequence of video pictures and to encode the processed block into an encoded picture that is part of an encoded video sequence. In one example, the video encoder (703) is used in place of the video encoder (403) in the example of FIG. 4.

[0081] In an HEVC example, the video encoder (703) receives a matrix of sample values ​​for a processing block, such as a predictive block, such as 8×8 samples. The video encoder (703) determines whether the processing block is best coded using intra mode, inter mode, or bi-predictive mode, e.g., using rate-distortion optimization. If the processing block is coded in intra mode, the video encoder (703) may use intra prediction techniques to code the processing block into a coded picture. If the processing block is coded in inter mode or bi-predictive mode, the video encoder (703) may use inter prediction techniques or bi-predictive techniques, respectively, to code the processing block into a coded picture. In certain video coding techniques, a merge mode may be an inter-picture prediction sub-mode in which motion vectors are derived from one or more motion vector predictors, but without the benefit of coded motion vector components outside the predictors. In certain other video coding techniques, there may be motion vector components applicable to the current block. In one example, the video encoder (703) includes other components, such as a mode decision module (not shown) for determining the mode of the processing blocks.

[0082] In the example of FIG. 7, the video encoder (703) includes an inter-encoder (730), an intra-encoder (722), a residual calculator (723), a switch (726), a residual encoder (724), a general controller (721), and an entropy coder (725), coupled together as shown in FIG.

[0083] The inter-encoder (730) is configured to receive samples of a current block (e.g., a processing block), compare the block with one or more reference blocks in a reference picture (e.g., blocks in previous and subsequent pictures), generate inter-prediction information (e.g., a description of redundant information due to inter-coding techniques, motion vectors, merge mode information), and calculate an inter-prediction result (e.g., a predicted block) based on the inter-prediction information using any suitable technique. In some examples, the reference picture is a decoded reference picture that is decoded based on the coded video information.

[0084] The intra encoder (722) is configured to receive samples of a current block (e.g., a processing block), possibly compare the block with blocks already encoded in the same picture, generate transformed and quantized coefficients, and possibly also generate intra prediction information (e.g., intra prediction direction information according to one or more intra encoding techniques). In one example, the intra encoder (722) also calculates an intra prediction result (e.g., a predicted block) based on the intra prediction information and a reference block in the same picture.

[0085] The general controller (721) is configured to determine general control data and control other components of the video encoder (703) based on the general control data. In one example, the general controller (721) determines the mode of the block and provides a control signal to the switch (726) based on the mode. For example, if the mode is an intra mode, the general controller (721) controls the switch (726) to select the result of the intra mode for use by the residual calculator (723), and controls the entropy encoder (725) to select intra prediction information and include the intra prediction information in the bitstream. If the mode is an inter mode, the general controller (721) controls the switch (726) to select the result of inter prediction for use by the residual calculator (723), and controls the entropy encoder (725) to select inter prediction information and include the inter prediction information in the bitstream.

[0086] The residual calculator (723) is configured to calculate a difference (residual data) between the received block and a prediction result selected from the intra-encoder (722) or the inter-encoder (730). The residual encoder (724) is configured to encode the residual data to generate transform coefficients based on the residual data. In one example, the residual encoder (724) is configured to transform the residual data from the spatial domain to the frequency domain to generate transform coefficients. The transform coefficients are then subjected to a quantization process to obtain quantized transform coefficients. In various embodiments, the video encoder (703) also includes a residual decoder (728). The residual decoder (728) is configured to perform an inverse transform to generate decoded residual data. The decoded residual data can be suitably used by the intra-encoder (722) and the inter-encoder (730). For example, the inter-encoder (730) can generate decoded blocks based on the decoded residual data and the inter-prediction information, and the intra-encoder (722) can generate decoded blocks based on the decoded residual data and the intra-prediction information. The decoded blocks are suitably processed to generate decoded pictures, which can be buffered in a memory circuit (not shown) and used as reference pictures in some examples.

[0087] The entropy encoder (725) is configured to format a bitstream to include the encoded block. The entropy encoder (725) is configured to include various information according to a suitable standard, such as the HEVC standard. In one example, the entropy encoder (725) is configured to include general control data, selected prediction information (e.g., intra-prediction information or inter-prediction information), residual information, and other suitable information in the bitstream. Note that in accordance with the disclosed subject matter, when encoding a block in a merged sub-mode of either the inter mode or the bi-prediction mode, the residual information is not present.

[0088] 8 shows a diagram of a video decoder (810) according to another embodiment of the present disclosure. The video decoder (810) is configured to receive encoded pictures that are part of an encoded video sequence and decode the encoded pictures to generate reconstructed pictures. In one example, the video decoder (810) is used in place of the video decoder (410) in the example of FIG. 4.

[0089] In the example of FIG. 8, the video decoder (810) includes an entropy decoder (871), an inter decoder (880), a residual decoder (873), a reconstruction module (874), and an intra decoder (872) coupled together as shown in FIG. 8.

[0090] The entropy decoder (871) may be configured to reconstruct from the coded picture certain symbols that represent the syntax elements of which the coded picture is composed. Such symbols may include, for example, prediction information (e.g., intra- or inter-prediction information, etc.) that may identify the mode in which the block is coded (e.g., intra- or inter-prediction mode, merged submode, or the latter two in another submode), certain samples or metadata used for prediction by the intra-decoder (872) or the inter-decoder (880), respectively, residual information, for example in the form of quantized transform coefficients, etc. In one example, if the prediction mode is an inter- or bi-prediction mode, the inter-prediction information is provided to the inter-decoder (880). If the prediction type is an intra-prediction type, the intra-prediction information is provided to the intra-decoder (872). The residual information may undergo inverse quantization and is provided to the residual decoder (873).

[0091] The inter decoder (880) is configured to receive inter prediction information and to generate inter prediction results based on the inter prediction information.

[0092] The intra decoder (872) is configured to receive intra prediction information and generate a prediction result based on the intra prediction information.

[0093] The residual decoder (873) is configured to perform inverse quantization to extract dequantized transform coefficients, and process the dequantized transform coefficients to transform the residual from the frequency domain to the spatial domain. The residual decoder (873) may also require certain control information (including quantizer parameters (QP)), which may be provided by the entropy decoder (871) (data path not depicted since this is only low volume control information).

[0094] The reconstruction module (874) is configured to combine, in the spatial domain, the residual output by the residual decoder (873) and the prediction result (output by the intra- or inter-prediction module, as the case may be) to form a reconstructed block, which may be part of a reconstructed picture, which may be part of a reconstructed video. It is noted that other suitable operations, such as a deblocking operation, may be performed to improve visual quality.

[0095] It should be noted that the video encoders (403), (603), (703) and the video decoders (410), (510), (810) may be implemented using any suitable technology. In some embodiments, the video encoders (403), (603), (703) and the video decoders (410), (510), (810) may be implemented using one or more integrated circuits. In other embodiments, the video encoders (403), (603), (703) and the video decoders (410), (510), (810) may be implemented using one or more processors executing software instructions.

[0096] This disclosure includes improvements to geometric partition modes with intra and inter prediction. In some embodiments, when inter and intra prediction are allowed for GPM, intra mode or intra prediction is not valid for some specified geometric partitions.

[0097] ITU-T VCEG (Q6 / 16) and ISO / IEC MPEG (JTC 1 / SC 29 / WG 11) published the H.265 / HEVC (High Efficiency Video Coding) standard in 2013 (version 1), 2014 (version 2), 2015 (version 3) and 2016 (version 4). In 2015, the two standards organizations jointly formed the Joint Video Exploration Team (JVET) to explore the possibility of developing the next video coding standard beyond HEVC. In October 2017, the two standards organizations issued a Joint Call for Proposals on Video Compression with Capability beyond HEVC (CfP). By February 15, 2018, a total of 22 CfP responses for standard dynamic range (SDR), 12 CfP responses for high dynamic range (HDR), and 12 CfP responses for 360 video category were submitted. In April 2018, all received CfP responses were evaluated at the 122 MPEG / 10th JVET meeting. As a result of this meeting, JVET formally started the standardization process for next-generation video coding beyond HEVC, the new standard was named VVC (Versatile Video Coding), and JVET was renamed Joint Video Experts Team. In 2020, ITU-T VCEG (Q6 / 16) and ISO / IEC MPEG (JTC 1 / SC 29 / WG 11) published the VVC video coding standard (version 1).

[0098] For each inter-predicted coding unit (CU), motion parameters are required due to the new coding features of VVC used to generate the inter-predicted samples. The motion parameters may include motion vectors, reference picture indexes, reference picture list usage indexes, and additional information. The motion parameters can be signaled in an explicit or implicit manner. If a CU is coded in skip mode, it can be associated with one PU, and no significant residual coefficients, coded motion vector deltas, or reference picture indexes may be required. If a CU is coded in merge mode, the motion parameters of the CU can be obtained from neighboring CUs. Neighboring CUs may include spatial and temporal candidates, and further schedules as introduced in VVC. The merge mode can be applied to any inter-predicted CU, not just skip mode. An alternative to the merge mode is explicit transmission of motion parameters, where the motion vectors, the corresponding reference picture indexes of each reference picture list, the reference picture list usage flag, and other necessary information can be explicitly signaled for each CU.

[0099] In VVC, the VVC Test model (VTM) reference software can include several new and sophisticated inter-prediction coding tools, which can be listed as follows: (1) Enhanced Merge Prediction (2) Merge motion vector difference (MMVD) (3) AMVP mode with symmetric MVD signaling (4) Affine motion compensation prediction (5) Subblock-based temporal motion vector prediction (SbTMVP) (6) Adaptive motion vector resolution (AMVR) (7) Motion field storage: 1 / 16 luma sample MV storage and 8x8 motion field compression (8) Bi-prediction with CU-level weights (BCW) (9) Bi-directional optical flow (BDOF) (10) Decoder side motion vector refinement (DMVR) (11) Combined inter and intra prediction (CIIP) (12) Geometric partitioning mode (GPM)

[0100] In VTM4, a merge candidate list can be constructed by including five types of candidates in the following order: 1) Spatial MVP from spatially neighboring CUs, 2) Temporal MVP from the same-positioned CU, 3) History-based MVP from a FIFO table, 4) Pairwise average MVP, and 5) Zero MV

[0101] The size of the merge list can be signaled in the slice header, and in VTM4 the maximum allowed size of the merge list can be 6. For each CU coded in merge mode, the index of the best merge candidate can be coded using truncated unary binarization (TU). The first bin of the merge index can be coded with the context, and bypass coding can be used for the other bins.

[0102] In the derivation of spatial candidates, the derivation of spatial merge candidates in VVC can be the same as that in HEVC. Up to four merge candidates can be selected from the candidates at the positions shown in FIG. 9. As shown in FIG. 9, a current block (901) can include neighboring blocks (902)-(906) at positions A0, A1, B0, B1, and B2, respectively. The derivation order of spatial merge candidates can be B1, A1, B0, A0, and B2. Position B2 may be considered only if any CU (or block) at positions A0, B0, B1, or A1 is not available (e.g., because the CU belongs to another slice or tile) or is intra-coded. After the candidate (or block) at position A1 is added, the addition of the remaining candidates (or blocks) can be subject to a redundancy check. The redundancy check ensures that candidates with the same motion information are removed from the merge list, which can improve the coding efficiency. In order to reduce the computational complexity, not all possible candidate pairs are considered in the redundancy check. Instead, only the candidate pairs linked by arrows in FIG. 10 may be considered. For example, the redundancy check can be applied to five candidate pairs, such as the candidate pair A1 and B1 and the candidate pair A1 and A0. A candidate may be added to the merge list only if the corresponding candidate used in the redundancy check does not contain the same motion information. For example, the candidate B0 may be added to the merge list only if the corresponding candidate B1 does not contain the same motion information.

[0103] In the derivation of a temporal candidate, only one candidate may be added to the merge list. For example, as shown in FIG. 11, in the derivation of a temporal merge candidate for a current CU (1114), a scaled motion vector can be derived based on the co-located CU (1104) belonging to the co-located reference picture (1112). The reference picture list used for the derivation of the co-located CU (1104) can be explicitly signaled in the slice header. The scaled motion vector of the temporal merge candidate can be obtained as shown by the dotted line (1102) in FIG. 11, which is scaled from the motion vector of the co-located CU (1104) using picture order count (POC) distances tb and td. tb can be defined as the POC difference between the reference picture (e.g., Curr_ref) (1106) of the current picture and the current picture (e.g., Curr_pic) (1108). td may be defined as the POC difference between the co-located picture's reference picture (e.g., Col_ref) 1110 and the co-located picture (e.g., Col_pic) 1112. The reference picture index of the temporal merge candidate may be set equal to 0.

[0104] As shown in Figure 12, the location of the temporal merge candidate can be selected between candidates C0 and C1. If the CU at location C0 is not available, is intra-coded, or is outside the current row of the CTU, then location C1 can be used. Otherwise, location C0 can be used to derive the temporal merge candidate.

[0105] A geometric partition mode (GPM) can be applied to inter prediction. GPM may be applied only to CUs with a size of 8×8 or larger than 8×8. GPM can be signaled, for example, using a CU level flag and can function as a type of merge mode. Other merge modes can include normal merge mode, MMVD mode, CIIP mode, and / or sub-block merge mode.

[0106] When GPM is used, a CU can be divided into two geometric partitions by using one of several partitioning schemes. In one embodiment, 64 different partitioning schemes can be applied in GPM. The 64 different partitioning schemes can be distinguished by 24 angles that are non-uniformly quantized between 0 and 360° with respect to the center of the CU up to a maximum of four edges. FIG. 13 shows the exemplary 24 angles applied in GPM. FIG. 14 shows an example of four possible partition edges related to an angle with index 3 in a CU (1402), each of which can be associated with a respective distance index. The distance index can indicate the distance to the center of the CU (1402). In GPM, each geometric partition in a CU can be inter-predicted using a respective motion vector. Furthermore, only one-way prediction may be allowed for each partition. For example, each partition can have one motion vector and one reference index. The constraint that only one-way prediction motion is allowed for each partition can ensure that only two motion compensation predictions are required per CU, which also applies to traditional bi-prediction.

[0107] If GPM is used for the current CU, a signal indicating the geometric partition index and two merge indexes (one for each partition) can be further signaled. The maximum GPM candidate size can be explicitly signaled, for example at the slice level. The number of maximum GPM candidate sizes can be specified by syntax binarization of the GPM merge index. After each of the two geometric partitions is predicted, the sample values ​​along the geometric partition edges can be adjusted using a blending process with adaptive weights. Accordingly, a prediction signal for the entire CU can be generated after the blending process. The transformation and quantization process can be further applied to the entire CU in other prediction modes. Finally, the motion field of the CU predicted using GPM can be stored.

[0108] To further improve compression efficiency, as in the VVC standard, template matching (TM) is available for decoder-side motion refinement. In TM mode, motion is refined by constructing a template from the left and top neighboring reconstructed samples, and the closest match between the template and a reference frame in the current picture can be determined.

[0109] TM can be applied to GPM. If a CU is coded with GPM, it can be determined whether TM is applied to refine the motion of each of the geometric partitions. If TM is selected, a template can be constructed using the left and top neighboring samples, and the motion can be further refined by finding the best match between the current template and a reference region with the same template pattern in a reference frame. The refined motion can be used to perform motion compensation of the geometric partition and can be further stored in the motion field.

[0110] To enhance coding performance beyond VVC, GPM can be applied to support inter and intra prediction. For example, a predefined intra prediction mode for (or related to) a geometric partition line can be selected from the merge candidate list for each geometric partition in the CU to which the GPM is applied, in addition to a motion vector. The intra prediction mode or inter prediction mode can be determined for each geometric partition based on a flag. If inter prediction is selected, a one-way prediction signal can be generated by MVs from the merge candidate list. Otherwise, if an intra prediction mode is selected, a one-way prediction signal can be generated from neighboring samples predicted from the specified index of the intra prediction mode. The variation of possible intra prediction modes can be limited by the geometry. Finally, the two one-way prediction signals can be blended similarly to normal GPM.

[0111] To reduce the complexity and signaling overhead, a variation of possible intra prediction modes can be studied (or defined). For example, the effect of the variation of possible intra prediction modes for GPM with inter and intra prediction was studied for two exemplary configurations. The first configuration tried only intra direction modes parallel and perpendicular to (or relative to) the geometric partition line. In addition to the intra angle modes parallel and perpendicular to (or relative to) the geometric partition line, the planar mode was also tested in the second configuration. Two or three possible intra prediction modes were tested for the geometric partition in GPM with inter and intra prediction. Table 1 shows pseudo code for the signaling of intra and inter prediction for GPM. [Table 1]

[0112] As shown in Table 1, when a GPM flag (e.g., gpm_flag) is 1 (or true), it indicates that GPM is applied to the current block. Thus, the current block can be partitioned into a first part (or first partition) and a second part (or second partition). The first partition index (e.g., partition_index0) can be analyzed (or coded) to determine whether the first partition is inter-coded or intra-coded. The second partition index (e.g., partition_index1) can be analyzed (or coded) to determine whether the second partition is inter-coded or intra-coded. In response to one of the first partition and the second partition being intra-coded and the other of the first partition and the second partition being inter-coded, a merge gpm partition index (e.g., merge_gpm_partition_idx) can be decoded. The merge gpm partition index can indicate a partition scheme from a plurality of partition schemes, such as the 64 different partition schemes shown in Figures 13-14. Furthermore, the intra mode index can be parsed (or coded) to indicate an intra mode from an intra mode list for one of the first and second partitions that are intra coded, and the merge index can be parsed to indicate a merge candidate from a merge candidate list for the other of the first and second partitions that are inter coded.

[0113] When an intra prediction mode is selected for the GPM, a flag can be signaled to indicate whether an intra prediction mode is used for the two geometric partitions. When a geometric partition is instructed to generate a prediction from neighboring samples by using an intra prediction mode, only a certain amount of possible intra prediction modes can be used. For example, for a GPM with inter and intra prediction, up to three possible intra prediction modes can be applied. The three possible intra prediction modes can include parallel, vertical and planar modes. In general, a limited number of intra prediction modes may result in a decrease in coding efficiency. However, allowing all intra prediction modes applicable to the GPM may also result in a decrease in coding efficiency, since some modes are not actually available or are inefficient.

[0114] In this disclosure, intra / inter mode information can be derived using a merge gpm partition index (e.g., merge_gpm_partition_idx) for each partition of the GPM. The merge gpm partition index can indicate a partition scheme from a plurality of partition schemes. In one example, the plurality of partition schemes can include 64 partition schemes shown in FIG. 13-FIG. 14. FIG. 15A, FIG. 15B, and FIG. 15C show three exemplary partitions based on the GPM. For example, as shown in FIG. 15A, a rectangular block (1502) can be a CU partitioned into partition A (1506) and partition B (1508) by a straight line (1504) inside the CU (1502). The straight line (1504) can be a partition line that is geometrically inside the CU (1502) and is indicated by the merge gpm partition index (e.g., merge_gpm_partition_idx).

[0115] In one embodiment, if both partitions of a CU cover the top left corner (0,0) of the CU (e.g., if the partition line passes through, extends to, or intersects the top left corner), which of the partitions is coded intra may be based on the width and height of the block (or CU). In one example, as shown in FIG. 15B, the width of the block (1510) is greater (or less) than the height of the block (1510). Thus, partition A (1512) may be coded with intra prediction and partition B (1514) may be coded with inter prediction. For example, if the width of the block (1510) is less than the height of the block (1510), partition B (1514) may be coded with intra prediction and partition A (1512) may be coded with inter prediction. In another example, if the width of the block (1510) is greater (or less) than the height of the block (1510), then partition A (1512) can be coded using inter prediction and partition B (1514) can be coded using intra prediction. In yet another example, if the width of the block (1510) is less than the height of the block (1510), then partition B (1514) can be coded using inter prediction and partition A (1512) can be coded using intra prediction.

[0116] In one embodiment, if both partitions cover the top-left corner (0,0) of the CU, which partition of the CU is coded intra can be based on the number of upper and left samples available for intra prediction. For example, as shown in FIG. 15B, the width of the block (1510) is greater (or less) than the height of the block (1510). If the block (1510) adjacent to the block (1510) is in another slice / tile (not shown) that is not currently available for intra prediction of the block (1510), and the left sample adjacent to the block (1510) is available for intra prediction, then partition A (1512) can be coded in intra mode.

[0117] In another embodiment, GPM intra / inter may not be allowed for a block partitioned by GPM if both the upper and left neighbors are not available for intra prediction. For example, if both the upper and left neighbors are not available for intra prediction, both partitions of the block by GPM can be inter coded.

[0118] In this disclosure, the partition that includes more (or a larger portion) of the pixels in the top-left corner (0,0) of the current CU can be coded in intra-prediction mode, and the other partition can be coded in inter-prediction mode.

[0119] In one embodiment, as shown in Figure 15A, partition A (1506) includes only the upper left corner pixels of the CU (1502). Therefore, partition A (1506) can be coded with intra prediction, and partition B (1508) can be coded with inter prediction.

[0120] In one embodiment, the larger portion may correspond to an angle formed by the partition line and a side of the block, or an angle of the partition at the top-left corner of the current CU. The larger angle may indicate that the partition includes a larger portion. As shown in FIG. 15B, a partition line (1522) may divide the pixels at the top-left corner, and angle A of partition A (1512) is larger than angle B of partition B (1514). Thus, partition A (1512) may include more (or a larger portion) of the pixels at the top-left corner. Thus, partition A (1512) may be coded with intra prediction, and partition B (1514) may be coded with inter prediction.

[0121] In another embodiment, if a first portion of a top corner pixel included in a first partition of a CU is equal to a second portion of a top corner pixel included in a second partition of the CU, whether the first partition is intra-coded or inter-coded and whether the second partition is intra-coded or inter-coded may be based on neighboring reference samples of the CU available for intra prediction. For example, whether the first partition is intra-coded or inter-coded and whether the second partition is intra-coded or inter-coded may be based on which of the top reference sample and the left reference sample are available for intra prediction and neighbor one of the first partition and the second partition of the CU.

[0122] In the example shown in Figure 15C, a partition line (1524) may divide the upper left pixel of a CU (1516), and angle A of partition A (1518) may be equal to angle B of partition B (1520). Thus, partition A (1518) and partition B (1520) may equally share the upper left pixel of the CU (1516). If partition B (1520) is adjacent to an upper reference sample available for intra prediction, partition B (1520) may be coded with intra prediction and partition A (1518) may be coded with inter prediction.

[0123] In another example shown in Figure 15C, if partition A (1518) is adjacent to the left reference sample of a CU (1518) available for intra prediction, partition A (1518) can be coded using intra prediction and partition B (1520) can be coded using inter prediction.

[0124] In this disclosure, the merge gpm partition index (e.g., merge_gpm_partition_idx) can be signaled first, followed by intra / inter mode information of partition_index0 and partition_index1 from the GPM. Pseudocode for signaling intra and inter prediction for GPM can be shown in Table 2, where the merge gpm partition index can be signaled before signaling intra / inter mode information of partition_index0 and partition_index1. [Table 2]

[0125] As shown in Table 2, when a GPM flag (e.g., gpm_flag) is 1 (or true), it indicates that GPM is applied to the current block. Thus, the current block can be partitioned into a first part (or first partition) and a second part (or second partition). A merge gpm partition index (e.g., merge_gpm_partition_idx) can be decoded. The merge gpm partition index can indicate a partition scheme from a plurality of partition schemes. The plurality of partition schemes can be as shown in Figures 13-14. The first partition index (e.g., partition_index0) can be analyzed (or coded) to determine whether the first partition is inter-coded or intra-coded. The second partition index (e.g., partition_index1) can be analyzed (or coded) to determine whether the second partition is inter-coded or intra-coded. If one of the first and second partitions is intra-coded and the other of the first and second partitions is inter-coded, the intra mode index can be parsed (or coded) to indicate an intra mode from an intra mode list of one of the first and second partitions that is intra-coded, and the merge index can be parsed to indicate a merge candidate from a merge candidate list of the other of the first and second partitions that is inter-coded.

[0126] In this disclosure, the first partition index (e.g., partition_index0) and the second partition index (e.g., partition_index1) may not be signaled to indicate whether the first partition is intra-coded or inter-coded and whether the second partition is intra-coded or inter-coded. When the merge gpm partition index (e.g., merge_gpm_partition_idx) is analyzed, whether the first partition is intra-coded or inter-coded and whether the second partition is intra-coded or inter-coded can be derived based on the location of the partition lines, which can be shown in Figures 15A-15C and their associated discussion. For example, as shown in Figure 15B, if a straight partition line (1522) intersects with the top left corner of a CU (1510) and the width of the CU (1510) is greater than or equal to the height of the CU (1510), then the first partition can be intra-coded and the second partition can be inter-coded.

[0127] In one embodiment, an intra and inter flag (e.g., one_intra_one_inter_flag) may be provided to replace the first partition index (e.g., partition_index0) and the second partition index (e.g., partition_index1) provided in Table 2. The intra and inter flag (e.g., one_intra_one_inter_flag) may indicate whether one of the first partition and the second partition is intra-coded and the other of the first partition and the second partition is inter-coded. For example, if the intra and inter flag (e.g., one_intra_one_inter_flag) is 1 (or true), this may indicate that one partition is intra-coded and the other is inter-coded. If the intra and inter flag (e.g., one_intra_one_inter_flag) is 0 (or false), both partitions can be inter-coded or inter-coded. Table 3 shows pseudocode for signaling intra and inter prediction for a GPM in which the intra and inter flags are included. [Table 3]

[0128] As shown in Table 3, when a GPM flag (e.g., gpm_flag) is 1 (or true), it indicates that GPM is applied to the current block. Thus, the current block may be partitioned into a first part (or first partition) and a second part (or second partition). A merge gpm partition index (e.g., merge_gpm_partition_idx) may be subsequently coded. The merge gpm partition index may indicate a partition scheme from a plurality of partition schemes. The plurality of partition schemes may be as shown in Figures 13-14. Furthermore, an intra and inter flag (e.g., one_intra_one_inter_flag) may be analyzed (or coded) to determine whether one of the first partition and the second partition is intra-coded and the other of the first partition and the second partition is inter-coded. If the intra and inter flags indicate that one of the first and second partitions is intra-coded and the other of the first and second partitions is inter-coded, then the intra mode index can be parsed (or coded) to indicate an intra mode from the intra mode list of one of the first and second partitions that is intra-coded, and the merge index can be parsed to indicate a merge candidate from the merge candidate list of the other of the first and second partitions that is inter-coded.

[0129] FIG. 16 shows a flow chart outlining an exemplary decoding process (1600) according to some embodiments of the present disclosure. FIG. 17 shows a flow chart outlining an exemplary encoding process (1700) according to some embodiments of the present disclosure. The proposed processes may be used individually or combined in any order. Furthermore, each of the processes (or embodiments), the encoder, and the decoder may be implemented by a processing circuit (e.g., one or more processors or one or more integrated circuits). In one example, the one or more processors execute a program stored on a non-transitory computer-readable medium.

[0130] In embodiments, the operations of any of the processes (e.g., 1600 and 1700) may be combined or arranged in any quantity or order as desired. In embodiments, two or more operations of the processes (e.g., 1600 and 1700) may be performed in parallel.

[0131] The processes (e.g., (1600) and (1700)) can be used in the reconstruction and / or encoding of a block to generate a prediction block for the block being reconstructed. In various embodiments, the processes (e.g., (1600) and (1700)) are performed by processing circuitry, such as processing circuitry in terminal devices (310), (320), (330), and (340), processing circuitry performing the functions of a video encoder (403), processing circuitry performing the functions of a video decoder (410), processing circuitry performing the functions of a video decoder (510), processing circuitry performing the functions of a video encoder (603), etc. In some embodiments, the processes (e.g., (1600) and (1700)) are implemented with software instructions, such that the processing circuitry performs the processes (e.g., (1600) and (1700)) when the processing circuitry executes the software instructions.

[0132] As shown in Figure 16, the process (1600) may begin at (S1601) and proceed to (S1610), where coding information for a coding unit (CU) in a current picture may be received from a coded video bitstream.

[0133] At (S1620), the CU may be partitioned into a first partition and a second partition based on a partition index in the coding information. The partition index may indicate a geometric partition mode (GPM) in which the CU is partitioned into the first partition and the second partition by a straight partition line.

[0134] At (S1630), based on the position of the straight partition line within the CU, it can be determined whether (i) a first prediction mode of a first partition of the CU is one of an intra mode and an inter mode, and (ii) a second prediction mode of a second partition of the CU is one of an intra mode and an inter mode.

[0135] At (S1640), a first partition of the CU may be reconstructed based on the determined first prediction mode, and a second partition of the CU may be reconstructed based on the determined second prediction mode.

[0136] The process then proceeds to (S1699) and ends.

[0137] In one example, a first prediction mode of a first partition can be determined as an intra mode and a second prediction mode of a second partition can be determined as an inter mode based on the width of the CU being greater than or equal to the height of the CU in response to the straight partition line intersecting the top left corner of the CU.

[0138] In another example, a first prediction mode of a first partition can be determined as an inter mode and a second prediction mode of a second partition can be determined as an intra mode based on the width of the CU being less than the height of the CU in response to the straight partition line intersecting the top left corner of the CU.

[0139] As yet another example, in response to a straight partition line intersecting the upper left corner of the CU, a first prediction mode of the first partition and a second prediction mode of the second partition can be determined based on which of the above reference samples and left reference samples adjacent to the CU are available for intra prediction.

[0140] For example, based on (i) the left reference sample is adjacent to the first partition of the CU and is available for intra prediction, and (ii) the top reference sample is unavailable for intra prediction, a first prediction mode of the first partition can be determined as an intra mode and a second prediction mode of the second partition can be determined as an inter mode.

[0141] In some embodiments, the first prediction mode of the first partition and the second prediction mode of the second partition can be determined based on which of the first partition and the second partition of the CU contains a larger portion of the top corner pixels of the CU.

[0142] In some embodiments, based on the first partition of the CU including a larger portion of the top corner pixels of the CU, a first prediction mode of the first partition can be determined as an intra mode and a second prediction mode of the second partition can be determined as an inter mode.

[0143] In some embodiments, in response to a first portion of an upper corner pixel included in the first partition being equal to a second portion of an upper corner pixel included in the second partition, the first prediction mode and the second prediction mode can be determined based on which of the upper reference sample and the left reference sample is adjacent to one of the first partition and the second partition.

[0144] In some embodiments, whether the first partition of the CU is intra-coded or inter-coded can be determined based on a first index. Whether the second partition of the CU is intra-coded or inter-coded can be determined based on a second index. In response to one of the first partition and the second partition being intra-coded and the other of the first partition and the second partition being inter-coded, an intra mode can be determined from an intra mode list of one of the first partition and the second partition that is intra-coded based on an intra mode index included in the coding information. A merge candidate for the inter mode can be determined from a merge candidate list of the other of the first partition and the second partition that is inter-coded based on a merge index included in the coding information.

[0145] In the process (1600), whether one of the first partition and the second partition of the CU is intra-coded and the other of the first partition and the second partition of the CU is inter-coded can be determined based on a flag included in the coding information. In response to one of the first partition and the second partition of the CU being intra-coded and the other of the first partition and the second partition of the CU being inter-coded, an intra mode can be determined from an intra mode list of one of the first partition and the second partition that is intra-coded based on an intra mode index included in the coding information. A merge candidate for the inter mode can be determined from a merge candidate list of the other of the first partition and the second partition that is inter-coded based on a merge index included in the coding information.

[0146] The process 1600 may be adapted as appropriate. Steps in the process 1600 may be modified or omitted. Additional steps may be added. Any suitable order of implementation may be used.

[0147] As shown in Figure 17, the process (1700) may start at (S1701) and proceed to (S1710), where a coding unit (CU) of a picture may be partitioned into a first partition and a second partition based on a geometric partition mode (GPM) in which the CU is partitioned into a first partition and a second partition by a straight partition line.

[0148] In (S1720), (i) whether a first prediction mode of a first partition of the CU is one of an intra mode and an inter mode, and (ii) whether a second prediction mode of a second partition of the CU is one of an intra mode and an inter mode can be determined based on the position of the straight partition line within the CU.

[0149] In (S1730), a predicted sample value of a first partition of the CU can be determined based on the determined first prediction mode, and a predicted sample value of a second partition of the CU can be determined based on the determined second prediction mode.

[0150] At (S1740), coding information for the CU may be generated. The coding information may indicate that a first prediction mode for a first partition of the CU and a second prediction mode for a second partition of the CU are determined based on a position of a straight partition line of the GPM within the CU.

[0151] The process then proceeds to (S1799) and ends.

[0152] The process 1700 may be adapted as appropriate. Steps in the process 1700 may be modified or omitted. Additional steps may be added. Any suitable order of implementation may be used.

[0153] The techniques described above can be implemented as computer software using computer-readable instructions and can be physically stored on one or more computer-readable media. For example, Figure 18 illustrates a computer system (1800) suitable for implementing certain embodiments of the disclosed subject matter.

[0154] Computer software can be coded using any suitable machine code or computer language and can be subject to assembly, compilation, linking, or similar mechanisms to produce code containing instructions that can be executed by one or more computer central processing units (CPUs), graphics processing units (GPUs), etc., either directly, or through interpretation, microcode execution, etc.

[0155] The instructions may be executed on various types of computers or components thereof, including, for example, personal computers, tablet computers, servers, smart phones, gaming devices, Internet of Things devices, etc.

[0156] 18 for computer system (1800) are exemplary in nature and are not intended to suggest any limitation as to the scope of use or functionality of the computer software implementing the embodiments of the present disclosure, nor should the arrangement of components be interpreted as having any dependency or requirement regarding any one or combination of components illustrated in the exemplary embodiment of computer system (1800).

[0157] The computer system (1800) may include certain human interface input devices that may be responsive to input by one or more human users through, for example, tactile input (e.g., keystrokes, swipes, data glove movements), audio input (e.g., voice, clapping), visual input (e.g., gestures), and olfactory input (not shown). Human interface devices may also be used to capture certain media that are not necessarily directly related to conscious human input, such as audio (e.g., speech, music, ambient sounds), images (e.g., scanned images, photographic images obtained from still image cameras), and video (e.g., two-dimensional video, three-dimensional video including stereoscopic video).

[0158] The input human interface devices may include one or more (only one of each is shown) of a keyboard (1801), a mouse (1802), a trackpad (1803), a touch screen (1810), a data glove (not shown), a joystick (1805), a microphone (1806), a scanner (1807), and a camera (1808).

[0159] The computer system (1800) may also include certain human interface output devices. Such human interface output devices may stimulate one or more of the human user's senses, for example, through haptic output, sound, light, and smell / taste. Such human interface output devices may include haptic output devices (e.g., haptic feedback via a touch screen (1810), data gloves (not shown), or joystick (1805); although there may be haptic feedback devices that do not act as input devices), audio output devices (e.g., speakers (1809), headphones (not shown)), visual output devices (e.g., screens (1810) including CRT screens, LCD screens, plasma screens, OLED screens; each may or may not have touch screen input capability, each may or may not have haptic feedback capability, some of which may output two-dimensional visual output or higher than three-dimensional output through such means as stereoscopic output; virtual reality glasses (not shown), holographic displays, and smoke tanks (not shown)), and printers (not shown).

[0160] The computer system (1800) may also include human accessible storage devices and associated media, such as optical media including CD / DVD ROM / RW (1820) along with CD / DVD or similar media (1821), thumb drives (1822), removable hard drives or solid state drives (1823), legacy magnetic media such as tapes and floppy disks (not shown), specialized ROM / ASIC / PLD based devices (not shown) such as security dongles, etc.

[0161] Those skilled in the art should also understand that the term "computer-readable medium" as used in connection with the presently disclosed subject matter does not encompass transmission media, carrier waves, or other transitory signals.

[0162] The computer system (1800) may also include an interface (1854) to one or more communication networks (1855). The networks may be, for example, wireless, wired, optical. The networks may further be local, wide area, metropolitan, in-vehicle and industrial, real-time, delay tolerant, etc. Examples of networks include Ethernet, WLAN, cellular networks including GSM, 3G, 4G, 5G, LTE, etc., TV wired or wireless wide area digital networks including cable television, satellite television, terrestrial broadcast television, in-vehicle and industrial including CANBus, etc. Certain networks usually require an external network interface adapter that is attached to a particular general-purpose data port or peripheral bus (1849) (e.g., a USB port of the computer system (1800)). Others are usually integrated into the core of the computer system (1800) by attachment to a system bus as described below (e.g., an Ethernet interface to a PC computer system or a cellular network interface to a smartphone computer system). Using any of these networks, computer system 1800 can communicate with other entities. Such communications may be unidirectional, receive only (e.g., broadcast television), unidirectional transmit only (e.g., CANbus to a specific CANbus device), or bidirectional, for example, to other computer systems using local or wide area digital networks. Specific protocols and protocol stacks may be used with each of these networks and network interfaces as described above.

[0163] The aforementioned human interface devices, human accessible storage devices, and network interfaces may be attached to a core (1840) of the computer system (1800).

[0164] The cores (1840) may include one or more central processing units (CPUs) (1841), graphics processing units (GPUs) (1842), specialized programmable processing units in the form of field programmable gate arrays (FPGAs) (1843), hardware accelerators for specific tasks (1844), graphics adapters (1850), etc. These devices may be connected through a system bus (1848), along with read only memory (ROM) (1845), random access memory (1846), internal mass storage devices (1847), such as internal non-user accessible hard drives, solid state drives (SSDs), etc. In some computer systems, the system bus (1848) may be accessible in the form of one or more physical plugs to allow expansion with additional CPUs, GPUs, etc. Peripheral devices may be attached directly to the core's system bus (1848) or through a peripheral bus (1849). In one example, a screen (1810) may be connected to the graphics adapter (1850). Architectures for peripheral buses include PCI, USB, and the like.

[0165] The CPU (1841), GPU (1842), FPGA (1843), and accelerator (1844) can execute certain instructions that, in combination, may constitute the above-mentioned computer code. The computer code may be stored in a ROM (1845) or a RAM (1846). Temporary data may also be stored in the RAM (1846), while persistent data may be stored, for example, in an internal mass storage device (1847). Rapid storage and retrieval from any of the memory devices may be enabled through the use of a cache memory that may be closely associated with one or more of the CPU (1841), GPU (1842), mass storage device (1847), ROM (1845), RAM (1846), etc.

[0166] The computer-readable medium can have computer code thereon for performing various computer-implemented operations. The medium and computer code may be those specially designed and constructed for the purposes of the present disclosure, or they may be of the kind well known and available to those having skill in the computer software arts.

[0167] By way of example and not limitation, a computer system having the architecture (1800), and in particular the core (1840), can provide functionality as a result of the processor (including CPU, GPU, FPGA, accelerator, etc.) executing software embodied in one or more tangible computer readable media. Such computer readable media can be user accessible mass storage as introduced above as well as media associated with the specific storage of the core (1840) of a non-transitory nature such as the mass storage device (1847) internal to the core or ROM (1845). Software implementing various embodiments of the present disclosure can be stored in such devices and executed by the core (1840). The computer readable media can include one or more memory devices or chips depending on the particular needs. The software can cause the core (1840) and in particular the processor therein (including CPU, GPU, FPGA, etc.) to perform certain processes or certain specific portions thereof described herein, including defining data structures stored in RAM (1846) and modifying such data structures according to the processes defined by the software. Additionally or alternatively, the computer system may provide functionality as a result of logic hardwired or otherwise embodied in circuitry (e.g., accelerator (1844)), which may operate in place of or together with software to perform particular processes or portions of particular processes described herein. Reference to software includes logic, and vice versa, as appropriate. Reference to a computer-readable medium may include circuitry (e.g., an integrated circuit (IC)) that stores software for execution, circuitry that embodies logic for execution, or both, as appropriate. The present disclosure encompasses any suitable combination of hardware and software.

[0168] Appendix A: Acronyms JEM: joint exploration model VVC: versatile video coding BMS: benchmark set MV: Motion Vector HEVC: High Efficiency Video Coding SEI: Supplementary Enhancement Information VUI: Video Usability Information GOP: Group of Pictures TU: Transform Unit PU: Prediction Unit CTU: Coding Tree Unit CTB: Coding Tree Block PB: Prediction Block HRD: Hypothetical Reference Decoder SNR: Signal Noise Ratio CPU: Central Processing Unit GPU: Graphics Processing Unit CRT: Cathode Ray Tube LCD: Liquid-Crystal Display OLED: Organic Light-Emitting Diode CD: Compact Disc DVD: Digital Video Disc ROM: Read-Only Memory RAM: Random Access Memory ASIC: Application-Specific Integrated Circuit PLD: Programmable Logic Device LAN: Local Area Network GSM: Global System for Mobile communications LTE: Long-Term Evolution CANBus: Controller Area Network Bus USB: Universal Serial Bus PCI: Peripheral Component Interconnect FPGA: Field Programmable Gate Areas SSD: solid-state drive IC: Integrated Circuit CU: Coding Unit

[0169] While this disclosure has described several exemplary embodiments, there are alterations, substitutions, and various substitute equivalents, which fall within the scope of this disclosure. Thus, it will be appreciated that those skilled in the art will be able to devise many systems and methods that, although not explicitly shown or described herein, embody the principles of the present disclosure and are thus within the spirit and scope of the present disclosure.

Claims

1. 1. A method of video decoding performed by a video decoder, comprising: receiving coding information of a coding unit (CU) of a current picture from a coded video bitstream; partitioning the CU into a first partition and a second partition based on a partition index in the coding information, the partition index indicating a geometric partition mode (GPM) in which the CU is partitioned into the first partition and the second partition by a straight partition line; determining, based on a position of the straight partition line within the CU, (i) whether a first prediction mode of the first partition of the CU is one of an intra mode and an inter mode, and (ii) whether a second prediction mode of the second partition of the CU is one of the intra mode and the inter mode; reconstructing the first partition of the CU based on the determined first prediction mode and reconstructing the second partition of the CU based on the determined second prediction mode; Including, The determining step includes: The method further includes determining the first prediction mode of the first partition and the second prediction mode of the second partition based on which of the first partition and the second partition of the CU includes a larger portion of pixels in an upper left corner of the CU.

2. The determining step includes:

2. The method of claim 1, further comprising: determining, based on the first partition of the CU including the larger portion of the upper left corner pixels of the CU, that the first prediction mode of the first partition is the intra mode and the second prediction mode of the second partition is the inter mode.

3. The determining step includes: if a first portion of the top-left corner pixel in the first partition is equal to a second portion of the top-left corner pixel in the second partition, 2. The method of claim 1, further comprising: determining the first prediction mode and the second prediction mode based on whether an upper reference sample and a left reference sample are adjacent to one of the first partition and the second partition.

4. 1. An apparatus including a processing circuit, Apparatus, wherein the processing circuitry is configured to perform the method of any one of claims 1 to 3.

5. A computer program product causing a computer to carry out the method according to any one of claims 1 to 3.

6. 1. A method of video encoding performed by a video encoder, comprising: Partitioning a coding unit (CU) of a picture into a first partition and a second partition based on a geometric partition mode (GPM), in which the CU is partitioned into the first partition and the second partition by a straight partition line; determining, based on a position of the straight partition line within the CU, (i) whether a first prediction mode of the first partition of the CU is one of an intra mode and an inter mode, and (ii) whether a second prediction mode of the second partition of the CU is one of an intra mode and an inter mode; determining a predicted sample value of the first partition of the CU based on the determined first prediction mode, and determining a predicted sample value of the second partition of the CU based on the determined second prediction mode; generating coding information for the CU, the coding information indicating that the first prediction mode of the first partition of the CU and the second prediction mode of the second partition of the CU are determined based on a position of the straight partition line of the GPM within the CU; Including, Determining, based on a position of the straight partition line within the CU, whether (i) a first prediction mode of the first partition of the CU is one of an intra mode and an inter mode, and (ii) a second prediction mode of the second partition of the CU is one of an intra mode and an inter mode, further comprising: The method further includes determining the first prediction mode of the first partition and the second prediction mode of the second partition based on which of the first partition and the second partition of the CU includes a larger portion of pixels in an upper left corner of the CU.

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