Video encoding and decoding method, device, computer readable medium and equipment

Abstract

A method, apparatus, computer-readable medium and device for video encoding and decoding are provided. The apparatus includes a processing circuit. Prediction information of a first block in an encoded video bitstream is decoded by the processing circuit. The first block is a non-square block, and the prediction information of the first block indicates a first intra-frame prediction mode in a first group of intra-frame prediction modes associated with the non-square block. The first group of intra-frame prediction modes includes a first number of intra-frame prediction modes, and the first number of intra-frame prediction modes is different from a second group of intra-frame prediction modes associated with a square block. The second number of intra-frame prediction modes to be deleted in the second group of intra-frame prediction modes is a positive integer determined based on the aspect ratio of the first block, and the first number is a positive integer determined based on the aspect ratio of the first block. Subsequently, at least one sample of the first block is reconstructed according to the first intra-frame prediction mode by the processing circuit.

Description

[0001] This application is a divisional application of an actively modified version of a patent application with a filing date of June 26, 2019, Chinese patent application number 201980018567.2, and invention name “Methods and related devices for video encoding and decoding”. Technical Field

[0002] This application describes embodiments that generally relate to video encoding. Background Art

[0003] The background description provided herein is for the purpose of presenting the content of the present application in general. The extent to which the work of the presently named inventors described in the background section and various aspects of this specification is performed does not indicate that it is prior art at the time of filing this application, and it is never explicitly or implicitly admitted that it is prior art of this application.

[0004] Video encoding and decoding can be performed using inter-picture prediction with motion compensation. Uncompressed digital video can include a series of pictures, each picture having a spatial size of, for example, 1920x1080 luma samples and associated chroma samples. The series of pictures can have a fixed or variable picture rate (also informally referred to as a frame rate) of, for example, 60 pictures per second or 60Hz. Uncompressed video has very high bit rate requirements. For example, 1080p604:2:0 video with 8 bits per sample (1920x1080 luma sample resolution at 60Hz frame rate) requires a bandwidth of nearly 1.5Gbit / s. One hour of such video requires more than 600GB of storage space.

[0005] One purpose of video encoding and decoding can be to reduce redundancy in the input video signal through compression. Compression can help reduce the bandwidth or storage space requirements mentioned above, in some cases by two orders of magnitude or more. Lossless compression and lossy compression, as well as combinations thereof, can be employed. Lossless compression refers to techniques that can reconstruct an exact copy of the original signal from the compressed original signal. When lossy compression is used, the reconstructed signal may not be the same as the original signal, but the distortion between the original signal and the reconstructed signal is small enough to make the reconstructed signal usable for the intended application. In the case of video, lossy compression is widely used. The amount of tolerable distortion depends on the application, for example, users of some consumer streaming applications can tolerate higher distortion than users of TV contribution applications. The achievable compression rate can reflect that higher tolerable / acceptable distortion can produce higher compression rates.

[0006] Video encoders and decoders may utilize a variety of broad categories of techniques including, for example: motion compensation, transforms, quantization, and entropy coding.

[0007] Video codec techniques may 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, pictures are spatially subdivided into blocks of samples. When all blocks of samples are encoded 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 can therefore be used as the first picture in a coded video bitstream and video session, or as a still image. The samples of the intra-block can be transformed, and the transform coefficients can be quantized before entropy coding. Intra-prediction can be a technique for minimizing sample values ​​in the pre-transform domain. In some cases, the smaller the DC value after the transform and the smaller the AC coefficient, the fewer bits are needed to represent the entropy-coded block at a given quantization step size.

[0008] Conventional intra-frame coding, such as is known from, for example, MPEG-2 generation coding techniques, does not use intra-frame prediction. However, some newer video compression techniques include techniques that attempt to extract information from, for example, surrounding sample data and / or metadata obtained during encoding / decoding of spatially adjacent and preceding data blocks in decoding order. Such techniques are hereinafter referred to as "intra-frame prediction" techniques. Note that, at least in some cases, intra-frame prediction uses only reference data from the current picture being reconstructed, and not reference data from reference pictures.

[0009] Intra-frame prediction can take many different forms. When more than one such technique can be used in a given video coding technique, the technique in the intra-frame prediction mode pair can be encoded. In some cases, a mode can have sub-modes and / or parameters, and these sub-modes and / or parameters can be encoded separately or included in the mode codeword. Which codeword is used for a given mode / sub-mode / parameter combination may have an impact on the coding efficiency gain through intra-frame prediction, and therefore the entropy coding technique used to convert the codeword into a bitstream.

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

[0011] refer to Figure 1 , depicted at the bottom right is a subset of 9 predictor directions known from the 35 possible predictor directions of H.265. The point (101) where the arrows converge represents the sample being predicted. The arrows represent the direction of the sample being predicted. For example, arrow (102) indicates that sample (101) is predicted from one or more samples in the upper right direction at an angle of 45 degrees to the horizontal. Similarly, arrow (103) indicates that sample (101) is predicted from one or more samples in the lower right direction at an angle of 22.5 degrees to the horizontal.

[0012] Still refer to Figure 1 , a square block (104) of 4x4 samples is depicted in the upper right corner (indicated by the bold dashed line). The square block (104) contains 16 samples, each of which is 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 in the Y dimension (from the top) and the first sample in the X dimension (from the left). Similarly, sample S44 is the fourth sample in the block (104) in both the Y and X dimensions. Since the size of the block is 4x4 samples, S44 is in the lower right corner. Figure 1 Reference samples are also shown in , following a similar numbering scheme. Reference samples are labeled with R and their Y position (e.g., row index) and X position (column index) relative to the block (104). In both H.264 and H.265, the prediction samples are adjacent to 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 occupied by a signaled prediction direction. For example, assume that the encoded video bitstream includes signaling that indicates a prediction direction consistent with arrow (102) for the block, that is, the sample is predicted from one or more prediction samples in the upper right corner at a 45 degree angle to the horizontal direction. In this case, samples S41, S32, S23, and S14 are predicted from the same R05. Sample S44 is then predicted based on R08.

[0014] In some cases, the values ​​of multiple reference samples may be combined, such as by interpolation, in order to calculate the reference sample, especially when the direction is not divisible by 45 degrees.

[0015] As video coding techniques have evolved, the number of possible directions has increased. In H.264 (2003), nine different directions could be represented. This number increased to 33 in H.265 (2013), and at the time of this disclosure, up to 65 directions are supported in JEM / VVC / BMS. Experiments have been conducted to identify the most likely directions, and certain techniques in entropy coding are used to represent those possible directions with a small number of bits, accepting a certain cost for less likely directions. In addition, the direction itself can sometimes be predicted based on neighboring directions used in neighboring blocks that have already been decoded.

[0016] Figure 2 is a schematic diagram 201 showing 65 intra prediction directions according to JEM, thereby showing the increasing number of prediction directions over time.

[0017] The mapping of the intra-prediction direction bits representing the direction in the coded video bitstream can vary from one video coding technique to another, and, for example, can range from a simple direct mapping of prediction direction to intra-prediction mode to codeword to complex adaptive schemes involving most likely modes and similar techniques. Those skilled in the art will be readily familiar with those techniques. However, in all cases, there may be certain directions that are statistically less likely to occur in the video content than certain other directions. Since the goal of video compression is to reduce redundancy, in a well-functioning video coding technique, those directions that are less likely to occur will be represented by a greater number of bits than directions that are likely to occur. Summary of the invention

[0018] Various aspects of the present application provide methods, devices, computer-readable media, and apparatus for video encoding and decoding.

[0019] According to one aspect of the present application, a method for video decoding is provided. In the disclosed method, prediction information of a first block is decoded from an encoded video bitstream, the first block is a non-square block, and the prediction information of the first block indicates a first set of intra-frame prediction modes associated with the non-square block, the first set of intra-frame prediction modes including at least one wide-angle intra-frame prediction mode;

[0020] Wherein, nWidth is defined as the width of the first block, nHeight is the height of the first block, 65 conventional intra prediction directions are used for intra prediction of the square block, the at least one wide-angle intra prediction mode is obtained by deleting some conventional intra prediction modes from the conventional intra prediction modes associated with the square block, and adding the same number of the wide-angle intra prediction modes to a set of new intra prediction modes for the rectangular block, the number of which depends on the aspect ratio of the first block, including:

[0021] When nWidth is greater than nHeight but less than twice of nHeight, deleting the six regular intra prediction modes including mode 2 to mode 7, and combining the six wide-angle intra prediction modes including mode 67 to mode 72 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or

[0022] When nWidth is equal to or greater than four times of nHeight, deleting the 10 regular intra prediction modes including modes 2 to 11, and combining the 10 wide-angle intra prediction modes including modes 67 to 76 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or

[0023] When nHeight is greater than nWidth but less than twice of nWidth, deleting the six regular intra prediction modes including mode 61 to mode 66, and combining the six wide-angle intra prediction modes of mode -1 to mode -6 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or

[0024] When nHeight is equal to or greater than four times of nWidth, 10 of the conventional intra-frame prediction modes including mode 57 to mode 66 are deleted, and 10 of the wide-angle intra-frame prediction modes including mode -1 to mode -10 are combined with the remaining conventional intra-frame prediction modes to form a new set of intra-frame prediction modes for the block. According to another aspect of the present application, a video decoding device is provided, the device comprising:

[0025] A processing circuit, the processing circuit being configured to:

[0026] decoding prediction information for a first block from an encoded video bitstream, the first block being a non-square block, and the prediction information for the first block indicating a first set of intra-prediction modes associated with the non-square block, the first set of intra-prediction modes comprising at least one wide-angle intra-prediction mode;

[0027] Wherein, nWidth is defined as the width of the first block, nHeight is defined as the height of the first block, and the processing circuit is specifically configured to delete some conventional intra-frame prediction modes from the conventional intra-frame prediction modes associated with the square block, and add the same number of the wide-angle intra-frame prediction modes to a set of new intra-frame prediction modes for the rectangular block to obtain at least one wide-angle intra-frame prediction mode, and the number depends on the aspect ratio of the first block in the following manner:

[0028] When nWidth is greater than nHeight but less than twice of nHeight, deleting the six regular intra prediction modes including mode 2 to mode 7, and combining the six wide-angle intra prediction modes including mode 67 to mode 72 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or

[0029] When nWidth is equal to or greater than four times of nHeight, deleting the 10 regular intra prediction modes including modes 2 to 11, and combining the 10 wide-angle intra prediction modes including modes 67 to 76 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or

[0030] When nHeight is greater than nWidth but less than twice of nWidth, deleting the six regular intra prediction modes including mode 61 to mode 66, and combining the six wide-angle intra prediction modes of mode -1 to mode -6 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or

[0031] When nHeight is equal to or greater than four times of nWidth, the 10 regular intra-frame prediction modes including mode 57 to mode 66 are deleted, and the 10 wide-angle intra-frame prediction modes including mode -1 to mode -10 are combined with the remaining regular intra-frame prediction modes to form a new set of intra-frame prediction modes for the block.

[0032] According to another aspect of the present application, a video encoding method is provided, the method comprising:

[0033] Receive the first block;

[0034] encoding prediction information for the first block into a video bitstream, wherein the first block is a non-square block, and the prediction information for the first block indicates that a first set of intra-prediction modes associated with the non-square block includes at least one wide-angle intra-prediction mode;

[0035] Wherein, nWidth is defined as the width of the first block, nHeight is the height of the first block, 65 conventional intra prediction directions are used for intra prediction of the square block, the at least one wide-angle intra prediction mode is modified by deleting some conventional intra prediction modes from the conventional intra prediction modes associated with the square block, and adding the same number of the wide-angle intra prediction modes to a set of new intra prediction modes for the rectangular block, the number of which depends on the aspect ratio of the first block, including:

[0036] When nWidth is greater than nHeight but less than twice of nHeight, deleting the six regular intra prediction modes including mode 2 to mode 7, and combining the six wide-angle intra prediction modes including mode 67 to mode 72 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or

[0037] When nWidth is equal to or greater than four times of nHeight, deleting the 10 regular intra prediction modes including modes 2 to 11, and combining the 10 wide-angle intra prediction modes including modes 67 to 76 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or

[0038] When nHeight is greater than nWidth but less than twice of nWidth, deleting the six regular intra prediction modes including mode 61 to mode 66, and combining the six wide-angle intra prediction modes of mode -1 to mode -6 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or

[0039] When nHeight is equal to or greater than four times of nWidth, the 10 regular intra-frame prediction modes including mode 57 to mode 66 are deleted, and the 10 wide-angle intra-frame prediction modes including mode -1 to mode -10 are combined with the remaining regular intra-frame prediction modes to form a new set of intra-frame prediction modes for the block.

[0040] According to another aspect of the present application, a video encoding device is provided, the device comprising:

[0041] an encoding module configured to receive a first block; encode prediction information of the first block into a video bitstream, wherein the first block is a non-square block, and the prediction information of the first block indicates a first set of intra-frame prediction modes associated with the non-square block, and the first set of intra-frame prediction modes includes at least one wide-angle intra-frame prediction mode;

[0042] Wherein, nWidth is defined as the width of the first block, nHeight is the height of the first block, 65 conventional intra prediction directions are used for intra prediction of the square block, and the encoding module is specifically configured to delete some conventional intra prediction modes from the conventional intra prediction modes associated with the square block, and add the same number of the wide-angle intra prediction modes to a set of new intra prediction modes for the rectangular block to obtain at least one wide-angle intra prediction mode, and the number depends on the aspect ratio of the first block in the following manner:

[0043] When nWidth is greater than nHeight but less than twice of nHeight, the six normal intra prediction modes including mode 2 to mode 7 are deleted, and the six wide-angle intra prediction modes including mode 67 to mode 72 are combined with the remaining normal intra prediction modes; or

[0044] When nWidth is equal to or greater than four times of nHeight, deleting the 10 regular intra prediction modes including modes 2 to 11, and combining the 10 wide-angle intra prediction modes including modes 67 to 76 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or

[0045] When nHeight is greater than nWidth but less than twice of nWidth, deleting the six regular intra prediction modes including mode 61 to mode 66, and combining the six wide-angle intra prediction modes of mode -1 to mode -6 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or

[0046] When nHeight is equal to or greater than four times of nWidth, the 10 regular intra-frame prediction modes including mode 57 to mode 66 are deleted, and the 10 wide-angle intra-frame prediction modes including mode -1 to mode -10 are combined with the remaining regular intra-frame prediction modes to form a new set of intra-frame prediction modes for the block.

[0047] Aspects of the present application also provide a non-transitory computer-readable medium storing computer-executable instructions. When the computer-executable instructions are executed by a computer to perform video encoding and decoding, the computer executes the video encoding and decoding method provided in the embodiments of the present application.

[0048] Aspects of the present application also provide a computer device, the computer device comprising:

[0049] A memory for storing computer executable instructions;

[0050] The processor is used to implement the video encoding and decoding method provided in the embodiment of the present application when executing the computer executable instructions or computer program stored in the memory. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Other features, properties and various advantages of the disclosed subject matter will become more apparent from the following detailed description and the accompanying drawings, in which:

[0052] Figure 1 is a schematic diagram of a subset of intra prediction modes according to H.265.

[0053] Figure 2 It is a schematic diagram of the intra prediction direction according to JEM.

[0054] Figure 3 is a schematic diagram of a simplified block diagram of a communication system (300) according to one embodiment.

[0055] Figure 4 is a schematic diagram of a simplified block diagram of a communication system (400) according to one embodiment.

[0056] Figure 5 is a schematic diagram of a simplified block diagram of a decoder according to one embodiment.

[0057] Figure 6 is a schematic diagram of a simplified block diagram of an encoder according to one embodiment.

[0058] Figure 7 A block diagram of an encoder according to another embodiment is shown.

[0059] Figure 8 A block diagram of a decoder according to another embodiment is shown.

[0060] Fig. 9 A schematic diagram showing wide angle mode in one example.

[0061] Fig.10 An example of remapping some regular intra prediction modes to wide-angle modes is shown.

[0062] Fig.11 Another example of remapping some regular intra prediction modes to wide-angle modes is shown.

[0063] Fig.12 Schematic diagram showing normal intra prediction direction and wide-angle intra prediction direction.

[0064] Fig.13 A flowchart outlining a decoding process according to an embodiment of the present application is shown.

[0065] Fig.14 is a schematic diagram of a computer system according to one embodiment. DETAILED DESCRIPTION

[0066] Figure 3 3 is a simplified block diagram of a communication system (300) according to an embodiment disclosed in the present application. The communication system (300) includes a plurality of terminal devices that can communicate with each other via, for example, a network (350). For example, the communication system (300) includes a first pair of terminal devices (310) and (320) interconnected via the network (350). Figure 3In an embodiment, the first terminal device performs unidirectional data transmission between (310) and (320). For example, the terminal device (310) may encode video data (e.g., a video picture stream collected by the terminal device (310)) for transmission to another terminal device (320) via the network (350). The encoded video data is transmitted in the form of one or more encoded video code streams. The terminal device (320) may receive the encoded video data from the network (350), decode the encoded video data to restore the video data, and display the video picture based on the restored video data. Unidirectional data transmission is more common in applications such as media services.

[0067] In another example, a communication system (300) includes a pair of terminal devices (330) and (340) that perform bidirectional transmission of encoded video data, which bidirectional transmission may occur, for example, during a video conference. For bidirectional data transmission, in one example, each of the terminal devices (330) and (340) may encode video data (e.g., a video picture stream collected by the terminal device) for transmission to the other of the terminal devices (330) and (340) via a network (350). Each of the terminal devices (330) and (340) may also receive the encoded video data transmitted by the other of the terminal devices (330) and (340), and may decode the encoded video data to restore the video picture, and may display the video picture on an accessible display device based on the restored video data.

[0068] exist Figure 3 In the example of, terminal device (310), terminal device (320), terminal device (330) and terminal device (340) may be shown as a server, a personal computer and a smart phone, but the principles disclosed in the present application may not be limited thereto. The embodiments disclosed in the present application are applicable to laptop computers, tablet computers, media players and / or dedicated video conferencing equipment. Network (350) represents any number of networks that transmit encoded video data between terminal devices (310), terminal devices (320), terminal devices (330) and terminal devices (340), including, for example, wired (wired) and / or wireless communication networks. Communication network (350) can exchange data in circuit switching and / or packet switching channels. Representative networks may include telecommunication networks, local area networks, wide area networks and / or the Internet. For the purposes of the present application, unless explained below, the architecture and topology of network (350) may be irrelevant to the operations disclosed in the present application.

[0069] As examples of applications of the disclosed subject matter, Figure 4The placement of the video encoder and video decoder in a streaming environment is shown. The disclosed subject matter is equally applicable to other video-enabled applications including, for example, video conferencing, digital TV, storing compressed video on digital media including CDs, DVDs, memory sticks, etc., and the like.

[0070] The streaming system may include an acquisition subsystem (413), which may include a video source (401), such as a digital camera, that creates an uncompressed video picture stream (402). In an example, the video picture stream (402) includes samples captured by a digital camera. The video picture stream (402), depicted as thick lines to emphasize the high amount of data compared to the encoded video data (404) (or the encoded video bitstream), may be processed by an electronic device (420), which includes a video encoder (403) coupled to the video source (401). The video encoder (403) may include hardware, software, or a combination of hardware and software to implement or implement various aspects of the disclosed subject matter as described in more detail below. The encoded video data (404) (or the encoded video bitstream (404)), depicted as thin lines to emphasize the lower amount of data compared to the video picture stream (402), may be stored on a streaming server (405) for future use. One or more streaming client subsystems, such as Figure 4 A client subsystem (406) and a client subsystem (408) in a streaming server (405) may access a streaming server (405) to retrieve a copy (407) and a copy (409) of the encoded video data (404). The client subsystem (406) may include, for example, a video decoder (410) in an electronic device (430). The video decoder (410) decodes the incoming copy (407) of the encoded video data and generates an output video picture stream (411) that can be presented on a display (412) (e.g., a display screen) or another presentation device (not depicted). In some streaming systems, the encoded video data (404), the video data (407), and the video data (409) (e.g., a video bitstream) may be encoded according to certain video encoding / compression standards. Examples of such standards include ITU-T H.265. In the example, the video coding standard under development is informally referred to as Versatile Video Coding (VVC), and the disclosed subject matter may be used in the context of VVC.

[0071] It should be noted that the electronic device (420) and the electronic device (430) may include other components (not shown). For example, the electronic device (420) may include a video decoder (not shown), and the electronic device (430) may also include a video encoder (not shown).

[0072] Figure 5is a block diagram of a video decoder (510) according to an embodiment disclosed in the present application. The video decoder (510) may be included in an electronic device (530). The electronic device (530) may include a receiver (531) (e.g., a receiving circuit). The video decoder (510) may be used to replace Figure 4 A video decoder (410) in an example of FIG.

[0073] The receiver (531) may receive one or more encoded video sequences to be decoded by the video decoder (510); in the same or another embodiment, one encoded video sequence is received at a time, wherein the decoding of each encoded video sequence is independent of the other encoded video sequences. The encoded video sequence may be received from a channel (501), which may be a hardware / software link to a storage device storing the encoded video data. The receiver (531) may receive the encoded video data and other data, such as encoded audio data and / or auxiliary data streams, which may be forwarded to their respective consuming entities (not shown). The receiver (531) may separate the encoded video sequence from the other data. To prevent network jitter, a buffer memory (515) may be coupled between the receiver (531) and the entropy decoder / parser (520) (hereinafter referred to as "parser (520)"). In some applications, the buffer memory (515) is part of the video decoder (510). In other cases, the buffer memory (515) may be provided external to the video decoder (510) (not shown). In other cases, a buffer memory (not shown) is provided outside the video decoder (510) to prevent network jitter, for example, and another buffer memory (515) may be configured inside the video decoder (510) to handle broadcast timing, for example. When the receiver (531) receives data from a storage / forward device with sufficient bandwidth and controllability or from an isochronous network, it may not be necessary to configure the buffer memory (515), or the buffer memory may be made smaller. For use on a service packet network such as the Internet, a buffer memory (515) may also be required, which may be relatively large and may advantageously have an adaptive size, and may be at least partially implemented in an operating system or a similar element (not shown) outside the video decoder (510).

[0074] The video decoder (510) may include a parser (520) to reconstruct symbols (521) from the encoded video sequence. The types of symbols include information used to manage the operation of the video decoder (510) and potential information used to control a display device such as a display device (512) (e.g., a display screen) that is not an integral part of the electronic device (530) but can be coupled to the electronic device (530), such as Figure 5As shown in . The control information for the display device may be a parameter set fragment (not indicated) of Supplemental Enhancement Information (SEI message) or Video Usability Information (VUI). The parser (520) may parse / entropy decode the received coded video sequence. The encoding of the coded video sequence may be performed according to a video coding technique or standard, and may follow various principles, including variable length coding, Huffman coding, arithmetic coding with or without context sensitivity, and the like. The parser (520) may extract a subgroup parameter set of at least one subgroup of the subgroups of pixels in the video decoder from the coded video sequence based on at least one parameter corresponding to the group. The subgroup may include a Group of Pictures (GOP), a picture, a tile, a slice, a macroblock, a Coding Unit (CU), a block, a Transform Unit (TU), a Prediction Unit (PU), and the like. The parser (520) may also extract information from the encoded video sequence, such as transform coefficients, quantizer parameter values, motion vectors, and so on.

[0075] The parser (520) may perform entropy decoding / parsing operations on the video sequence received from the buffer memory (515), thereby creating symbols (521).

[0076] Depending on the type of coded video picture or portion of coded video picture (e.g., inter- and intra-pictures, inter- and intra-blocks) and other factors, the reconstruction of the symbol (521) may involve multiple different units. Which units are involved and how they are involved may be controlled by subgroup control information parsed by the parser (520) from the coded video sequence. For the sake of brevity, such subgroup control information flow between the parser (520) and the multiple units below is not described.

[0077] In addition to the functional blocks already mentioned, the video decoder (510) can be conceptually subdivided into several functional units as described below. In a practical embodiment operating under commercial constraints, many of these units interact closely with each other and can be at least partially integrated with each other. However, for the purpose of describing the disclosed subject matter, the conceptual subdivision into the following functional units is appropriate.

[0078] The first unit is a sealer / inverse transform unit (551). The sealer / inverse transform unit (551) receives quantized transform coefficients as symbols (521) from the parser (520) and control information, including which transform method to use, block size, quantization factor, quantization scaling matrix, etc. The sealer / inverse transform unit (551) can output a block including sample values, which can be input into the aggregator (555).

[0079] In some cases, the output samples of the scaler / inverse transform unit (551) may belong to an intra-coded block; that is, a block that does not use predictive information from a previously reconstructed picture, but may use predictive information from a previously reconstructed portion of the current picture. Such predictive 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 reconstructed information extracted from a current picture buffer (558). For example, the current picture buffer (558) buffers a partially reconstructed current picture and / or a fully reconstructed current picture. In some cases, the aggregator (555) adds the prediction information generated by the intra-prediction unit (552) to the output sample information provided by the scaler / inverse transform unit (551) on a per-sample basis.

[0080] In other cases, the output samples of the scaler / inverse transform unit (551) may belong to an inter-frame coded and potentially motion compensated block. In this case, the motion compensated prediction unit (553) may access the reference picture memory (557) to extract samples for prediction. After the extracted samples are motion compensated according to the symbols (521) belonging to the block, these samples may be added to the output of the scaler / inverse transform unit (551) (in this case referred to as residual samples or residual signals) by the aggregator (555) to generate output sample information. The acquisition of prediction samples by the motion compensated prediction unit (553) from the address in the reference picture memory (557) may be controlled by a motion vector, and the motion vector is provided to the motion compensated prediction unit (553) in the form of a symbol (521), which may have, for example, X, Y and reference picture components. Motion compensation may also include interpolation of sample values ​​extracted from the reference picture memory (557) when using sub-sample accurate motion vectors, motion vector prediction mechanisms, and the like.

[0081] The output samples of the aggregator (555) may be subjected to various loop filtering techniques in a loop filter unit (556). The video compression techniques may include in-loop filter techniques controlled by parameters included in the coded video sequence (also referred to as the coded video bitstream) and available to the loop filter unit (556) as symbols (521) from the parser (520), however, the video compression techniques may also be responsive to meta-information obtained during decoding of a coded picture or a previous (in decoding order) portion of the coded video sequence, as well as to previously reconstructed and loop filtered sample values.

[0082] The output of the loop filter unit (556) may be a sample stream that may be output to a display device (512) and stored in a reference picture memory (557) for subsequent inter-picture prediction.

[0083] Once fully reconstructed, certain coded pictures may be used as reference pictures for future prediction. For example, once the coded picture corresponding to the 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) may become part of the reference picture memory (557), and a new current picture buffer may be reallocated before starting to reconstruct a subsequent coded picture.

[0084] The video decoder (510) may perform decoding operations according to a predetermined video compression technique, such as in the ITU-T H.265 standard. The encoded video sequence may conform to the syntax specified by the video compression technique or standard used, in the sense that the encoded video sequence follows the syntax of the video compression technique or standard and the profile recorded in the video compression technique or standard. Specifically, the profile may select certain tools from all the tools available in the video compression technique or standard as the only tools available for use under the profile. For compliance, the complexity of the encoded video sequence is also required to be within the range defined by the hierarchy of the video compression technique or standard. In some cases, the hierarchy limits the maximum picture size, the maximum frame rate, the maximum reconstruction sampling rate (measured in, for example, mega samples per second), the maximum reference picture size, etc. In some cases, the limits set by the hierarchy may be further limited by the Hypothetical Reference Decoder (HRD) specification and metadata of the HRD buffer management signaled in the encoded video sequence.

[0085] In an embodiment, 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. The additional data may be used by the video decoder (510) to properly decode the data and / or 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.

[0086] Figure 6 6 is a block diagram of a video encoder (603) according to an embodiment disclosed in the present application. 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 to replace Figure 4 A video encoder (403) in an example.

[0087] The video encoder (603) can be used to obtain the video source (601) (not Figure 6 In another embodiment, the video source (601) is a part of the electronic device (620) to receive video samples, and the video source can collect video images to be encoded by the video encoder (603). In another embodiment, the video source (601) is a part of the electronic device (620).

[0088] The video source (601) may provide a source video sequence in the form of a digital video sample stream to be encoded by the video encoder (603), which may have any suitable bit depth (e.g., 8-bit, 10-bit, 12-bit, ...), any color space (e.g., BT.601 Y CrCB, RGB, ...), and any suitable sampling structure (e.g., Y CrCb 4:2:0, Y CrCb 4:4:4). In a media service system, the video source (601) may be a storage device storing previously prepared videos. In a video conferencing system, the video source (601) may be a camera that captures local image information as a video sequence. The video data may be provided as a plurality of separate pictures that are given motion when viewed sequentially. The pictures themselves may be constructed as a spatial pixel array, where each pixel may include one or more samples depending on the sampling structure, color space, etc. used. The relationship between pixels and samples may be easily understood by those skilled in the art. The following description focuses on samples.

[0089] According to an embodiment, the video encoder (603) may encode and compress pictures of a source video sequence into an encoded video sequence (643) in real time or under any other time constraints required by the application. Implementing an appropriate encoding speed is a function of the controller (650). In some embodiments, the controller (650) controls other functional units as described below and is functionally coupled to the other functional units. For the sake of brevity, coupling is not indicated in the figure. The parameters set by the controller (650) may include rate control related parameters (picture skipping, quantizer, lambda value of rate distortion optimization technology, etc.), picture size, group of pictures (GOP) layout, maximum motion vector search range, etc. The controller (650) may be configured to have other suitable functions that are related to the video encoder (603) optimized for a certain system design.

[0090] In some embodiments, the video encoder (603) is configured to operate in an encoding loop. As a simple description, in an example, the encoding loop may include a source encoder (630) (e.g., responsible for creating symbols, such as a symbol stream, based on an input picture to be encoded and a reference picture) and a (local) decoder (633) embedded in the video encoder (603). The decoder (633) reconstructs the symbols to create sample data in a manner similar to that of the (remote) decoder (because in the video compression technology considered by the disclosed subject matter, any compression between the symbols and the encoded video code stream 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 that are independent of the decoder location (local or remote), the contents of the reference picture memory (634) are also bit-accurately corresponding between the local encoder and the remote encoder. In other words, the reference picture samples "seen" by the prediction part of the encoder are exactly the same as the sample values ​​that the decoder will "see" when using the prediction during decoding. This basic principle of reference picture synchronization (and the drift that occurs when synchronization cannot be maintained, eg due to channel errors) is also used in some related techniques.

[0091] The operation of the "local" decoder (633) can be combined with the above Figure 5 The "remote" decoder described in detail for the video decoder (510) is identical. However, additional brief reference is made to Figure 5 , when symbols are available and the entropy encoder (645) and parser (520) are capable of losslessly encoding / decoding the symbols into an encoded video sequence, the entropy decoding portion of the video decoder (510), including the buffer memory (515) and the parser (520), may not be fully implemented in the local decoder (633).

[0092] At this point, it can be observed that any decoder technology other than the parsing / entropy decoding present in the decoder must also be present in the corresponding encoder in substantially the same functional form. For this reason, the disclosed subject matter focuses on the decoder operation. The description of encoder technology can be simplified because encoder technology is mutually inverse to the decoder technology described comprehensively. A more detailed description is only needed in certain areas and is provided below.

[0093] During operation, in some examples, the source encoder (630) may perform motion compensated predictive coding. The motion compensated predictive coding predictively encodes an input picture with reference to one or more previously encoded pictures from a video sequence designated as "reference pictures." In this way, the encoding engine (632) encodes the difference between a pixel block of the input picture and a pixel block of a reference picture that may be selected as a prediction reference for the input picture.

[0094] The local video decoder (633) may decode the encoded video data of the picture that may be designated as the reference picture based on the symbol created by the source encoder (630). The operation of the encoding engine (632) may advantageously be a lossy process. When the encoded video data is available at the video decoder ( Figure 6 When the video sequence is decoded at a remote location (not shown), the reconstructed video sequence may typically be a copy of the source video sequence with some errors. The local video decoder (633) replicates the decoding process that may be performed by the video decoder on the reference picture and may cause the reconstructed reference picture to be stored in the reference picture cache (634). In this way, the video encoder (603) may locally store a copy of the reconstructed reference picture that has common content (absent transmission errors) with the reconstructed reference picture that will be obtained by the remote video decoder.

[0095] The predictor (635) may perform a prediction search for the encoding engine (632). That is, for a new picture to be encoded, the predictor (635) may search the reference picture memory (634) for sample data (as candidate reference pixel blocks) or certain metadata, such as reference picture motion vectors, block shapes, etc., that may serve as appropriate prediction references for the new picture. The predictor (635) may operate on a pixel block by pixel block basis to find a suitable prediction reference. In some cases, as determined by the search results obtained by the predictor (635), the input picture may have prediction references taken from multiple reference pictures stored in the reference picture memory (534).

[0096] The controller (650) may manage encoding operations of the source encoder (630), including, for example, setting parameters and subgroup parameters for encoding video data.

[0097] The outputs of all the above functional units may be entropy encoded in an entropy encoder (645). The entropy encoder (545) performs lossless compression on the symbols generated by the various functional units according to techniques known to those skilled in the art, such as Huffman coding, variable length coding, arithmetic coding, etc., thereby converting the symbols into a coded video sequence.

[0098] The transmitter (640) may buffer the encoded video sequence created by the entropy encoder (645) in preparation for transmission over a communication channel (660), which may be a hardware / software link to a storage device where the encoded video data will be stored. The transmitter (640) may combine the encoded video data from the video encoder (603) with other data to be transmitted, such as encoded audio data and / or ancillary data streams (source not shown).

[0099] The controller (650) may manage the operation of the video encoder (603). During encoding, the controller (650) may assign a certain coded picture type to each coded picture, but this may affect the coding techniques that can be applied to the corresponding picture. For example, a picture may generally be assigned to any of the following picture types:

[0100] An intra picture (I picture) may be a picture that can be encoded and decoded without using any other picture in the sequence as a prediction source. Some video codecs allow different types of intra pictures, including, for example, Independent Decoder Refresh ("IDR") pictures. Those skilled in the art are aware of the variations of I pictures and their corresponding applications and features.

[0101] A predictive picture (P picture) may be a picture that can be encoded and decoded using intra prediction or inter prediction, which uses at most one motion vector and a reference index to predict sample values ​​for each block.

[0102] Bidirectional predictive pictures (B pictures), which can be pictures that can be encoded and decoded using intra prediction or inter prediction, which uses up to two motion vectors and reference indices to predict the sample values ​​of each block. Similarly, multiple predictive pictures can use more than two reference pictures and associated metadata for reconstructing a single block.

[0103] The source picture may typically be spatially subdivided into blocks of samples (e.g., blocks of 4×4, 8×8, 4×8, or 16×16 samples), and coded block by block. These blocks may be predictively coded with reference to other (already coded) blocks, which are determined by the coding allocation applied to the block's corresponding picture. For example, a block of an I picture may be non-predictively coded, or the block may be predictively coded (spatial prediction or intra prediction) with reference to an already coded block of the same picture. A block of a P picture may be predictively coded by spatial prediction with reference to one previously coded reference picture or by temporal prediction. A block of a B picture may be predictively coded by spatial prediction with reference to one or two previously coded reference pictures or by temporal prediction.

[0104] The video encoder (603) may perform encoding operations according to a predetermined video encoding technique or standard, such as ITU-T H.265 Recommendation. In operation, the video encoder (603) may perform various compression operations, including predictive encoding operations that exploit temporal and spatial redundancy in an input video sequence. Thus, the encoded video data may conform to the syntax specified by the video encoding technique or standard used.

[0105] In an embodiment, the transmitter (640) may transmit additional data when transmitting the encoded video. The source encoder (630) may include such data as part of the encoded video sequence. The additional data may include other forms of redundant data such as temporal / spatial / SNR enhancement layers, redundant pictures and slices, Supplementary Enhancement Information (SEI) messages, Visual Usability Information (VUI) parameter set fragments, etc.

[0106] The captured video may be taken as a plurality of source pictures (video pictures) in a temporal sequence. Intra-picture prediction (often simplified to intra-prediction) exploits spatial correlations in a given picture, while inter-picture prediction exploits (temporal or other) correlations between pictures. In an example, a particular picture being encoded / decoded is divided into blocks, and the particular picture being encoded / decoded is referred to as the current picture. When a block in the current picture is similar to a reference block in a reference picture that was previously encoded in the video and is still buffered, the block in the current picture may be encoded by a vector called a motion vector. The motion vector points to a reference block in a reference picture, and in the case where multiple reference pictures are used, the motion vector may have a third dimension that identifies the reference picture.

[0107] In some embodiments, bidirectional prediction techniques may be used in inter-picture prediction. According to the bidirectional prediction technique, two reference pictures are used, for example, a first reference picture and a second reference picture that are both before the current picture in the video in decoding order (but may be in the past and future in display order, respectively). A block in the current picture may be encoded by a first motion vector pointing to a first reference block in the first reference picture and a second motion vector pointing to a second reference block in the second reference picture. Specifically, the block may be predicted by a combination of the first reference block and the second reference block.

[0108] In addition, merge mode technology can be used in inter-picture prediction to improve coding efficiency.

[0109] According to some embodiments disclosed in the present application, predictions such as inter-picture prediction and intra-picture prediction are performed in units of blocks. For example, according to the HEVC standard, pictures in a video picture sequence are divided into coding tree units (CTUs) for compression, and the CTUs in the pictures 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), which are a luminance CTB and two chrominance CTBs. Each CTU can also be recursively split into one or more coding units (CUs) using a quadtree. For example, a 64×64 pixel CTU can be split into a 64×64 pixel CU, or 4 32×32 pixel CUs, or 16 16×16 pixel CUs. In the example, each CU is analyzed to determine a prediction type for the CU, such as an inter-prediction type or an intra-prediction type. Depending on temporal and / or spatial predictability, the CU is split into one or more prediction units (PUs). Typically, each PU includes a luma prediction block (PB) and two chroma PBs. In an embodiment, the prediction operation in encoding (encoding / decoding) is performed in units of prediction blocks. Taking the 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, and the like.

[0110] Figure 7 is a diagram of a video encoder (703) according to another embodiment disclosed in the present application. The video encoder (703) is configured to receive a processed block (e.g., a prediction block) of sample values ​​within a current video picture in a video picture sequence, and encode the processed block into an encoded picture that is part of an encoded video sequence. In this embodiment, the video encoder (703) is used to replace Figure 4A video encoder (403) in an embodiment.

[0111] In an HEVC embodiment, a video encoder (703) receives a matrix of sample values ​​for a processing block, such as a prediction block of 8×8 samples. The video encoder (703) uses, for example, rate-distortion (RD) optimization to determine whether to use intra mode, inter mode, or bidirectional prediction mode to best encode the processing block. When encoding the processing block in intra mode, the video encoder (703) may use intra prediction techniques to encode the processing block into an encoded picture; and when encoding the processing block in inter mode or bidirectional prediction mode, the video encoder (703) may use inter prediction or bidirectional prediction techniques to encode the processing block into an encoded picture, respectively. In some video encoding techniques, the merge mode may be an inter-picture prediction submode, in which motion vectors are derived from one or more motion vector predictors without the aid of encoded motion vector components external to the predictor. In some other video encoding techniques, there may be motion vector components applicable to the subject block. In an embodiment, the video encoder (703) includes other components, such as a mode decision module (not shown) for determining the processing block mode.

[0112] exist Figure 7 In the example of FIG. 7 , the video encoder ( 703 ) includes Figure 7 Shown are an inter-frame encoder (730), an intra-frame encoder (722), a residual calculator (723), a switch (726), a residual encoder (724), a general controller (721), and an entropy encoder (725) coupled together.

[0113] The inter-frame 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 a previous picture and a subsequent picture), generate inter-frame prediction information (e.g., redundant information description, motion vector, merge mode information according to the inter-frame coding technology), and calculate an inter-frame prediction result (e.g., a predicted block) based on the inter-frame prediction information using any suitable technology.

[0114] The intra encoder (722) is configured to receive samples of a current block (e.g., a processing block), compare the block to an already encoded block in the same picture in some cases, generate quantized coefficients after transformation, and in some cases also generate intra prediction information (e.g., intra prediction direction information according to one or more intra coding techniques).

[0115] 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 an 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, when the mode is intra mode, the general controller (721) controls the switch (726) to select the intra mode result for use by the residual calculator (723), and controls the entropy encoder (725) to select intra prediction information and add the intra prediction information to the bitstream; and when the mode is inter mode, the general controller (721) controls the switch (726) to select the inter prediction result for use by the residual calculator (723), and controls the entropy encoder (725) to select the inter prediction information and add the inter prediction information to the bitstream.

[0116] The residual calculator (723) is configured to calculate the difference (residual data) between the received block and the prediction result selected from the intra-frame encoder (722) or the inter-frame encoder (730). The residual encoder (724) is configured to operate based on the residual data to encode the residual data to generate transform coefficients. In an example, the residual encoder (724) is configured to convert the residual data in the frequency domain and generate transform coefficients. The transform coefficients are then subjected to a quantization process to obtain quantized transform coefficients.

[0117] The entropy encoder (725) is configured to format the codestream to produce an encoded block. The entropy encoder (725) includes various information according to a suitable standard, such as the HEVC standard. In an example, the entropy encoder (725) is configured to include general control data, selected prediction information (such as intra-frame prediction information or inter-frame prediction information), residual information, and other suitable information in the codestream. It should be noted that according to the disclosed subject matter, when the block is encoded in the inter-frame mode or the merge sub-mode of the bidirectional prediction mode, there is no residual information.

[0118] Figure 8 is a diagram of a video decoder (810) according to another embodiment disclosed in the present application. The video decoder (810) is configured to receive an encoded image as part of an encoded video sequence and decode the encoded image to generate a reconstructed picture. In an example, the video decoder (810) is used to replace Figure 4 A video decoder (410) is shown in an example.

[0119] exist Figure 8 In this example, the video decoder (810) includes Figure 8 An entropy decoder (871), an inter-frame decoder (880), a residual decoder (873), a reconstruction module (874) and an intra-frame decoder (872) coupled together are shown in FIG.

[0120] The entropy decoder (871) may be configured to reconstruct certain symbols from the encoded picture, which represent syntax elements constituting the encoded picture. Such symbols may include, for example, a mode for encoding the block (e.g., intra mode, inter mode, bidirectional prediction mode, a merged submode of the latter two, or another submode), prediction information (e.g., intra prediction information or inter prediction information) that can identify certain samples or metadata for prediction by the intra decoder (872) or the inter decoder (880), respectively, residual information in the form of, for example, quantized transform coefficients, and the like. In an example, when the prediction mode is inter or bidirectional prediction mode, the inter prediction information is provided to the inter decoder (880); and when the prediction type is an intra prediction type, the intra prediction information is provided to the intra decoder (872). The residual information may be subjected to inverse quantization and provided to the residual decoder (873).

[0121] The inter-frame decoder (880) is configured to receive inter-frame prediction information and generate an inter-frame prediction result based on the inter-frame prediction information.

[0122] The intra decoder (872) is configured to receive intra prediction information and generate a prediction result based on the intra prediction information.

[0123] The residual decoder (873) is configured to perform inverse quantization to extract dequantized transform coefficients, and process the dequantized transform coefficients to convert the residual from the frequency domain to the spatial domain. The residual decoder (873) may also require certain control information (to include quantizer parameters QP), and this information may be provided by the entropy decoder (871) (the data path is not indicated because this is only low-volume control information).

[0124] The reconstruction module (874) is configured to combine the residual output by the residual decoder (873) with the prediction result (which may be output by the inter-frame prediction module or the intra-frame prediction module) in the spatial domain to form a reconstructed block, which may be part of a reconstructed picture, which in turn may be part of a reconstructed video. It should be noted that other suitable operations such as deblocking operations may be performed to improve visual quality.

[0125] It should be noted that the video encoder (403), video encoder (603), and video encoder (603) and video decoder (410), video decoder (510), and video decoder (810) may be implemented using any suitable technology. In an embodiment, the video encoder (403), video encoder (603), and video encoder (703) and video decoder (410), video decoder (510), and video decoder (810) may be implemented using one or more integrated circuits. In another embodiment, the video encoder (403), video encoder (603), and video encoder (703) and video decoder (410), video decoder (510), and video decoder (810) may be implemented using one or more processors that execute software instructions.

[0126] According to some aspects of the present application, for intra-frame prediction, a wide angle mode may be used to compress video and reduce bandwidth or storage space requirements.

[0127] Fig. 9 A schematic diagram (900) of a wide-angle mode in an example is shown. Typically, intra prediction is performed at a 45 degree angle to the upper right corner (corresponding to Fig. 9 The arrow pointing to 34 in the middle) to the 45 degree direction at the lower left corner (corresponding to Fig. 9 The range of the prediction direction beyond the range of the prediction direction covered by the conventional intra prediction mode may correspond to the wide-angle intra prediction mode.

[0128] In some examples, a wide-angle intra prediction direction is associated with one regular intra prediction direction. For example, a wide-angle intra prediction direction and its associated intra prediction direction capture the same directionality, but use reference samples on the opposite side (left column or top row). In an example, the wide-angle intra prediction mode is signaled by sending a 1-bit flag for the associated direction with an available wide-angle "flip mode". Fig. 9 In the example of , the first direction with the arrow pointing to 35 is the wide angle intra prediction direction and is associated with the second direction with the arrow pointing to 03. Therefore, the first direction may be signaled by sending a 1-bit flag for the second direction.

[0129] In one embodiment, in the case of 33-directional angular intra prediction, the available new modes are limited to the 10 directional modes of the top right directional mode (i.e., mode 34 when 35 conventional intra modes are applied) and the bottom left corner mode (i.e., mode 2 when 35 conventional intra modes are applied) closest to the 45-degree diagonal. The actual sample prediction process follows the prediction process in HEVC or VVC.

[0130] exist Fig. 9 In the example of , 33 intra prediction directions associated with modes 2 to 34 are shown. In the example, when the width of the block is greater than the height of the block, the directions associated with modes 35 and 36 can be used as wide-angle intra prediction directions. Modes 3 and 4 can then have an additional flag that indicates whether to use the indicated mode or to use the flipped wide-angle directions under modes 35 and 36. In some examples (e.g., Versatile Video Coding Test Model 1 (VTM1)), square and non-square blocks are all supported in quadtree, binary, and ternary tree (QT+BT+TT) partition structures), when the intra prediction designs for square and non-square blocks use the same intra prediction modes for square blocks (e.g., modes 2 to 34), the intra prediction modes (e.g., Fig. 9 Modes 2 to 34 in the example are not efficient for non-square blocks. Wide-angle prediction modes (e.g. Fig. 9 Modes 35 and 36 in the example may be used to more efficiently encode non-square blocks.

[0131] In some examples, the signaling of wide-angle intra prediction depends on the intra prediction mode. Therefore, when parsing the wide-angle control flag, there is a parsing dependency problem (the intra prediction mode needs to be reconstructed during the parsing process).

[0132] In some embodiments, some intra-prediction modes for square blocks are remapped to wide-angle prediction modes for non-square blocks. In an example, during the remapping process, some intra-prediction modes for square blocks are deleted from a set of intra-prediction modes originally used for square blocks, and the same number of wide-angle prediction modes are added to the set of intra-prediction modes to form a new set of intra-prediction modes for some non-square blocks. Thus, a certain number of modes in the set of intra-prediction modes are changed, while other modes remain the same. In some examples, the certain number of modes that have been changed depends on the block shape, such as the aspect ratio of the block.

[0133] For square blocks, a set of conventional intra-frame prediction modes can be used for intra-frame prediction, and the mode numbers for the set of conventional intra-frame prediction modes can be 35, 67, etc. For non-square blocks, certain modes can be deleted from the set of conventional intra-frame prediction modes, and the same number of wide-angle modes (the same as the number of deleted modes) can be combined with the remaining conventional intra-frame prediction modes to form a new set of intra-frame prediction modes. Therefore, in the example, the signaling mode indexes for non-square blocks and square blocks are the same, and non-square and square blocks share the same mode encoding algorithm. In the case of 35 conventional intra-frame prediction modes, the indices of the added upper right wide-angle mode are mode 35, mode 36, mode 37, mode 38, etc., and the indices of the added lower left wide-angle mode are mode-1, mode-2, mode-3, mode-4, etc.

[0134] Fig.10 and Fig.11 Two examples of remapping some regular intra prediction modes to wide-angle modes are shown. Fig.10 In the example, mode 2-34 is Fig.10 Modes 2-34 are included in Modes 0 and 1 to form a set of conventional intra prediction modes for square blocks. Fig.10 In the example of , mode 2 and mode 3 are deleted from the set of conventional intra prediction modes (as shown by the dashed line). In addition, wide angle mode 35 and mode 36 are added (as shown by the dotted line), wherein the direction of mode 35 is opposite to that of mode 3 (as shown by (1001)), and the direction of mode 36 is opposite to that of mode 4 (as shown by (1002)). Therefore, modes 4-36 are included in mode 0 and mode 1 to form a new set of intra prediction modes for certain non-square blocks.

[0135] exist Fig.11 In the example, mode 33 and mode 34 are deleted (as shown by the dashed line), and wide-angle mode-1 and mode-2 are added (as shown by the dotted line). The direction of mode-1 is opposite to that of mode 33 (as shown by (1101)), and the direction of mode-2 is opposite to that of mode 32 (as shown by (1102)). Therefore, mode-2 and mode-1 as well as mode 2-32 are included in mode 0 and mode 1 to form a new set of intra prediction modes for certain non-square blocks.

[0136] In one embodiment, the angular distance between the removed normal mode and the added wide-angle mode is greater than 90 degrees and less than or equal to 180 degrees. For example, when there are 35 normal intra-frame prediction modes and the width is greater than the height, modes 2 to 5 are deleted, and wide-angle modes 35 to 38 are added; when the height is greater than the width, modes 31 to 34 are deleted, and modes -1 to -4 are added. In another example, there are 67 normal intra-frame prediction modes, when the width is greater than the height, modes 2 to 9 are deleted, and modes 67 to 74 are added; when the height is greater than the width, modes 59 to 66 are deleted, and modes -1 to -8 are added.

[0137] In an alternative embodiment, the deleted normal modes and added wide-angle modes are in opposite directions. For example, when there are 35 normal intra-frame prediction modes, when the width is greater than the height, modes 3 to 6 are deleted, and wide-angle modes 35 to 38 are added; when the height is greater than the width, modes 30 to 33 are deleted, and wide-angle modes -1 to -4 are added. For another example, when there are 67 normal intra-frame prediction modes, when the width is greater than the height, modes 3 to 10 are deleted, and wide-angle modes 67 to 74 are added; when the height is greater than the width, modes 58 to 65 are deleted, and wide-angle modes -1 to -8 are added.

[0138] In an alternative embodiment, when the width is greater than the height, some regular modes starting from the lower left direction are deleted, and the same number of wide-angle modes are added starting from the upper right direction. Otherwise, when the height is greater than the width, some modes starting from the upper right direction are deleted, and the same number of wide-angle modes starting from the lower left direction are added.

[0139] For example, when there are 35 regular intra prediction modes and the width is greater than the height, modes 2 to 5 are deleted and wide-angle modes 35 to 38 are added; when the height is greater than the width, modes 31 to 34 are deleted and wide-angle modes -1 to -4 are added.

[0140] In an alternative embodiment, the number of deleted normal intra prediction modes is fixed for all non-square block shapes. For all non-square blocks, N normal intra prediction modes are deleted and N wide angle modes are added accordingly. For example, when 35 normal modes are used, N can be 1 to 7, when 67 normal modes are used, N can be 2 to 14, and when 129 normal intra prediction modes are used, N can be 4 to 28.

[0141] In a sub-embodiment, N may be signaled in a high-level syntax element (e.g., in a sequence parameter set (SPS), a picture parameter set (PPS), a slice header) or in a common syntax element or parameter for a picture region.

[0142] In one example, when there are 35 regular intra prediction modes, 4 regular intra prediction modes are deleted, and when there are 67 regular intra prediction modes, 8 regular intra prediction modes are deleted.

[0143] In an alternative embodiment, the number of regular intra prediction modes that are deleted depends on the shape of the non-square block.

[0144] In some examples, when width / height<=2 or height / width<=2 (aspect ratio=width / height, 1<aspect ratio<=2 or 1 / 2<=aspect ratio<1), M regular intra-frame prediction modes are deleted. In addition, when width / height>=4 or height / width>=4 (aspect ratio>=4 or aspect ratio<=1 / 4), N regular intra-frame prediction modes are deleted. In addition, in the example, when 2<aspect ratio<4 or 1 / 4<aspect ratio<1 / 2, P regular intra-frame prediction modes are deleted. In one example, M is not equal to N. In one example, when there are 35 regular intra-frame prediction modes, M is equal to 3 and N is equal to 5; and when there are 67 regular intra-frame prediction modes, M is equal to 6 and N is equal to 10. P can be the same as M or N, or different from M or N.

[0145] In one sub-embodiment, M and N may be signaled in a high-level syntax element (e.g., in a sequence parameter set (SPS), in a picture parameter set (PPS), in a slice header) or in a common syntax element or parameter for a picture region. In another example, the number of deleted conventional intra prediction modes depends on coding information, including but not limited to block width, block height, and the ratio of block width to block height, and block area size.

[0146] In an alternative embodiment, the deleted regular intra-frame prediction mode starts from the lower left diagonal mode (i.e., mode 2 when 35 modes are applied) or the upper right diagonal mode (i.e., mode 34 when 35 modes are applied), and the added wide-angle mode starts from the nearest angle after the lower left diagonal mode or the upper right diagonal mode (i.e., mode -1 or mode 35).

[0147] In some examples, the deleted normal modes and the added wide-angle modes may be continuous or discontinuous. In one example, when there are 35 normal intra-frame prediction modes and the width is greater than the height, modes 2 to 5 are deleted, and wide-angle modes 35 to 38 are added. In another example, when there are 35 normal intra-frame prediction modes and the width is greater than the height, modes 2 to 5 are deleted, and wide-angle modes 35, 37, 38, and 39 are added.

[0148] In an alternative embodiment, unused / deleted regular intra prediction modes are used to indicate the added wide mode. Therefore, the unused regular intra prediction modes are still signaled, but the meaning of these unused regular intra prediction modes is converted to the added wide mode. For example, when the width is greater than the height, mode 2 is deleted, but mode 2 is still signaled. For a non-square block, when the decoder decodes mode 2 and the width is greater than the height, the decoder converts mode 2 to mode 35.

[0149] In an alternative embodiment, in order to derive the most probable mode (MPM) of the current block, when the intra prediction of the neighboring block exceeds the intra prediction direction range of the current block, the mode of the neighboring block will be mapped to the nearest direction covered by the intra prediction direction range of the current block. For example, if the current block is a square block, and the block to its left is a non-square block, and the mode number of the block to the left is 35. Mode 35 is not within the mode range of the current block. Therefore, the mode of the block to the left is mapped to the nearest mode 34 covered by the mode range of the current block.

[0150] In some embodiments, an intra prediction process is performed using wide-angle prediction for a rectangular block. The inputs received by the intra prediction process include, for example, an intra prediction mode (represented by predModeIntra), the width of the current block (represented by nWidth), the height of the block (represented by nHeight), neighboring samples (represented by p[x][y], where (x=-1, y=-1 to nWidth+nHeight-1) (x=0 to nWidth+nHeight-1, y=-1)), and a variable cIdx specifying the color component of the current block. The intra prediction process can generate prediction samples predSamples[x][y], where x=0 to nWidth-1, y=0 to nHeight-1.

[0151] In some embodiments, the intra prediction process is performed based on a mapping between an intra prediction mode predModeIntra and an angle parameter intraPredAngle.

[0152] Fig.12A schematic diagram showing 43 intra-frame prediction directions is shown. The 43 intra-frame prediction directions include 33 normal intra-frame prediction directions corresponding to modes 2 to 34 of normal intra-frame prediction modes, and include 5 wide-angle directions extending beyond mode 34 (as shown in modes 35 to 39) and 5 wide-angle directions extending beyond mode 2 (as shown in modes -1 to -5).

[0153] Fig.12 A top-ruler and a left-ruler are also shown. In some examples, the angle parameter intraPredAngle is measured according to the top-ruler or the left-ruler. Table 1 specifies a mapping table between intra prediction modes predModeIntra and angle parameters intraPredAngle.

[0154] predModeIntra -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 intraPredAngle 114 79 60 49 39 - 32 26 21 17 13 9 5 2 0 -2 predModeIntra 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 intraPredAngle -5 -9 -13 -17 -21 -26 -32 -26 -21 -17 -13 -9 -5 -2 0 2 5 predModeIntra 29 30 31 32 33 34 35 36 37 38 39 intraPredAngle 9 13 17 21 26 32 39 49 60 79 114

[0155] Table 1

[0156] In an example, the input intra prediction mode predModeIntra is one of the deleted regular intra prediction modes, and the input intra prediction mode predModeIntra is converted into a wide mode based on an aspect ratio (nWidth / nHeight) of a current block.

[0157] For example, when nWidth / nHeight=2 and 2<=predModeIntra<=4, predModeIntra←predModeIntra+33. Specifically, when the width nWidth of the block is twice the height nHeight of the block, 3 regular intra prediction modes (mode 2, mode 3, and mode 4) are deleted from a set of regular intra prediction modes, and 3 wide-angle modes (mode 35, mode 36, and mode 37) are combined with the remaining regular intra prediction modes to form a new set of intra prediction modes for the block. When the input intra prediction mode predModeIntra corresponds to one of the deleted modes, the intra prediction mode predModeIntra is converted to a wide-angle mode.

[0158] In addition, when nWidth / nHeight>=4 and 2<=predModeIntra<=6, predModeIntra←predModeIntra+33. Specifically, when the width nWidth of the block is greater than or equal to four times the height nHeight of the block. Delete 5 regular intra-frame prediction modes (mode 2, mode 3, mode 4, mode 5, mode 6) from a set of regular intra-frame prediction modes, and combine 5 wide-angle modes (mode 35, mode 36, mode 37, mode 38 and mode 39) with the remaining regular intra-frame prediction modes to form a new set of intra-frame prediction modes for the block. When the input intra-frame prediction mode predModeIntra corresponds to one of the deleted modes, the intra-frame prediction mode predModeIntra is converted to a wide-angle mode.

[0159] In addition, when nHeight / nWidth=2 and 32<=predModeIntra<=34, predModeIntra←predModeIntra-35. Specifically, when the height nHeight of the block is twice the width nWidth of the block, 3 regular intra prediction modes (mode 34, mode 33, and mode 32) are deleted from a set of regular intra prediction modes, and 3 wide-angle modes (mode-1, mode-2, and mode-3) are combined with the remaining regular intra prediction modes to form a new set of intra prediction modes for the block. When the input intra prediction mode predModeIntra corresponds to one of the deleted modes, the intra prediction mode predModeIntra is converted to a wide-angle mode.

[0160] In addition, when nHeight / nWidth>=4 and 30<=predModeIntra<=34, predModeIntra←predModeIntra-35. Specifically, when the height nHeight of the block is greater than or equal to four times the width nWidth of the block, 5 conventional intra-frame prediction modes (mode 34, mode 33, mode 32, mode 32, mode 30) are deleted from a set of conventional intra-frame prediction modes, and 5 wide-angle modes (mode-1, mode-2, mode-3, mode-4 and mode-5) are combined with the remaining conventional intra-frame prediction modes to form a new set of intra-frame prediction modes for the block. When the input intra-frame prediction mode predModeIntra corresponds to one of the deleted modes, the intra-frame prediction mode predModeIntra is converted to a wide-angle mode.

[0161] Then, based on the intra prediction mode predModeIntra, the corresponding angle parameter intraPredAngle may be determined (eg, based on Table 1). In addition, the prediction samples predSamples[x][y] may be calculated based on the angle parameter intraPredAngle based on a suitable video coding standard (eg, HEVC standard).

[0162] In another example, 65 conventional intra prediction directions are used for intra prediction of square blocks. Figure 2 As shown, 65 conventional intra prediction directions correspond to modes 2-66 belonging to conventional intra prediction modes. Modes 2-66, mode 0 (planar mode), and mode 1 (DC mode) form a set of 67 intra prediction modes for square blocks. In some embodiments, some conventional intra prediction modes are deleted, and the same number of wide-angle modes are added to a new set of intra prediction modes for rectangular blocks, and the number depends on the aspect ratio of the rectangular block.

[0163] In some embodiments, an intra prediction process is performed for a rectangular block (current block) using wide-angle prediction. The inputs received by the intra prediction process include, for example, an intra prediction mode predModeIntra, the width nWidth of the current block, the height nHeight of the block, and neighboring samples (represented by p[x][y], where (x=-1, y=-1 to nWidth+nHeight-1)(x=0 to nWidth+nHeight-1, y=-1)). The intra prediction process can generate prediction samples predSamples[x][y], x=0 to nWidth-1, y=0 to nHeight-1.

[0164] In the example, the variable whRatio is defined to be equal to min(abs(Log2(nWidth / nHeight)), 2). When nWidth is greater than nHeight but less than two times nHeight, whRatio is less than 1. When nWidth is equal to two times nHeight, whRatio is equal to 1. When nWidth is greater than two times nHeight but less than four times nHeight, whRatio is a value in the range (1,2). When nWidth is four times nHeight, whRatio is equal to 2. When nWidth is greater than four times nHeight, whRatio is equal to 2.

[0165] Similarly, when nHeight is greater than nWidth but less than twice nWidth, whRatio is less than 1. When nHeight is equal to twice nWidth, whRatio is equal to 1. When nHeight is greater than twice nWidth but less than four times nWidth, whRatio is a value in the range (1,2). When nHeight is four times nWidth, whRatio is equal to 2. When nHeight is greater than four times nWidth, whRatio is equal to 2. Therefore, whRatio is a function of the block shape and does not depend on the block orientation.

[0166] In an example, the input intra prediction mode predModeIntra is one of the deleted regular intra prediction modes, and the input intra prediction mode predModeIntra is converted to the wide mode based on whRatio of the current block.

[0167] For example, when nWidth is greater than nHeight but less than twice nHeight, whRatio is less than 1, 6 conventional intra prediction modes (modes 2-7) are deleted from a set of conventional intra prediction modes, and then 6 wide-angle modes (modes 67-72) are combined with the remaining conventional intra prediction modes to form a new set of intra prediction modes for the block. When the input intra prediction mode predModeIntra corresponds to one of the deleted modes (greater than or equal to 2 and less than 8), the intra prediction mode predModeIntra is converted to a wide-angle mode by adding 65.

[0168] In addition, when nWidth is equal to or greater than four times nHeight, 10 conventional intra prediction modes (modes 2 to 11) are deleted from a set of conventional intra prediction modes, and 10 wide-angle modes (modes 67 to 76) are combined with the remaining conventional intra prediction modes to form a new set of intra prediction modes for the block. When the input intra prediction mode predModeIntra corresponds to one of the deleted modes (greater than or equal to 2 and less than 12), the intra prediction mode predModeIntra is converted to a wide-angle mode by adding 65.

[0169] In addition, when nHeight is greater than nWidth but less than twice nWidth, whRatio is less than 1, and 6 conventional intra prediction modes (modes 61-66) are deleted from a set of conventional intra prediction modes, and 6 wide-angle modes (modes -1 to -6) are combined with the remaining conventional intra prediction modes to form a new set of intra prediction modes for the block. When the input intra prediction mode predModeIntra corresponds to one of the deleted modes (greater than or equal to 61 and less than 67), the intra prediction mode predModeIntra is converted to a wide-angle mode by subtracting 67.

[0170] In addition, when nHeight is equal to or greater than four times nWidth, 10 conventional intra prediction modes (modes 57-66) are deleted from a set of conventional intra prediction modes, and 10 wide-angle modes (modes -1 to -10) are combined with the remaining conventional intra prediction modes to form a new set of intra prediction modes for the block. When the input intra prediction mode predModeIntra corresponds to one of the deleted modes (greater than or equal to 57 and less than 67), the intra prediction mode predModeIntra is converted to a wide-angle mode by subtracting 67.

[0171] Then, based on the intra prediction mode predModeIntra, the corresponding angle parameter intraPredAngle may be determined, for example, based on a lookup table.Then, the prediction samples predSamples[x][y] may be calculated according to the angle parameter intraPredAngle based on a suitable video coding standard such as the HEVC standard.

[0172] Fig.13A flow chart of a process (1300) according to an embodiment of the present application is shown. The process (1300) can be used to reconstruct a block encoded in intra-frame mode, thereby generating a prediction block for the block being reconstructed. In various embodiments, the process (1300) is performed by a processing circuit such as the following processing circuits: a processing circuit in a terminal device (310), a processing circuit in a terminal device (320), a processing circuit in a terminal device (330) and a terminal device (340), a processing circuit that performs the functions of a video encoder (403), a processing circuit that performs the functions of a video decoder (410), a processing circuit that performs the functions of a video decoder (510), a processing circuit that performs the functions of an intra-frame prediction module (552), a processing circuit that performs the functions of a video encoder (603), a processing circuit that performs the functions of a predictor (635), a processing circuit that performs the functions of an intra-frame encoder (722), a processing circuit that performs the functions of an intra-frame decoder (872), etc. In some embodiments, the process (1300) is implemented in software instructions, so when the processing circuit executes the software instructions, the processing circuit performs the process (1300). The process starts from (S1301) and proceeds to (S1310).

[0173] At (S1310), prediction information for a block is decoded. In an example, a processing circuit decodes prediction information for a block from an encoded video bitstream. In some examples, the block is a non-square block, and the prediction information for the block indicates a first intra-prediction mode in a first set of intra-prediction modes for non-square blocks. The first set of intra-prediction modes has a first number of different intra-prediction modes (e.g., one or more wide-angle modes) that are not in a second set of intra-prediction modes for square blocks. The first set of intra-prediction modes does not include a second number of intra-prediction modes that are lost (deleted or unused) in the second set of intra-prediction modes. In some embodiments, the first number of different intra-prediction modes and the second number of lost intra-prediction modes are functions of an aspect ratio of the block (which indicates the shape of the block). Both the first number and the second number are positive integers. In some embodiments, the first number is equal to the second number.

[0174] At (S1320), samples of the block are reconstructed according to the first intra prediction mode. In some examples, based on the first intra prediction mode, corresponding angle parameters may be determined, for example, based on a lookup table. Samples of the block may then be calculated based on angle parameters based on a suitable video coding standard such as the HEVC standard. The process then proceeds to S1399 and ends.

[0175] The above techniques may be implemented as computer software using computer-readable instructions and physically stored in one or more computer-readable media. Fig.14 A computer system (1400) suitable for implementing certain embodiments of the disclosed subject matter is shown.

[0176] Computer software may be encoded using any suitable machine code or computer language that may be subjected to assembly, compilation, linking or similar mechanisms to create code comprising instructions that may be executed directly by one or more computer central processing units (CPUs), graphics processing units (GPUs), etc., or through decoding, microcode, etc.

[0177] 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, IoT devices, etc.

[0178] Fig.14 The components of the computer system (1400) shown are exemplary in nature and are not intended to impose any limitation on the scope of use or functionality of computer software implementing embodiments of the present application. The configuration of components should not be interpreted as having any dependency or requirement related to any one or combination of components shown in the exemplary embodiment of the computer system (1400).

[0179] The computer system (1400) may include certain human-machine interface input devices. Such human-machine interface input devices may respond to input from 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), olfactory input (not depicted). The human-machine interface device may also be used to capture certain media that are not necessarily directly related to human conscious input, such as audio (e.g., voice, music, ambient sound), images (e.g., scanned images, photographic images obtained from a still image camera), video (e.g., two-dimensional video, three-dimensional video including stereoscopic video), etc.

[0180] The input human-machine interface device may include one or more of the following (only one of each is shown): keyboard (1401), mouse (1402), touch pad (1403), touch screen (1410), data gloves (not shown), joystick (1405), microphone (1406), scanner (1407), camera (1408).

[0181] The computer system (1400) may also include certain human-machine interface output devices. Such human-machine interface output devices may stimulate one or more human user senses, for example, through tactile output, sound, light, and smell / taste. Such human-machine interface output devices may include tactile output devices (e.g., tactile feedback of a touch screen (1410), a data glove (not shown), or a joystick (1405), but may also be a tactile feedback device that is not an input device), an audio output device (e.g., a speaker (1409), headphones (not shown)), a visual output device (e.g., a screen (1410) including a CRT screen, an LCD screen, a plasma screen, an OLED screen, each with or without a touch screen input function, each with or without a tactile feedback function, some of which are capable of outputting two-dimensional visual output or output in more than three dimensions through devices such as stereoscopic image output, virtual reality glasses (not depicted), holographic displays and smoke boxes (not depicted), and printers (not depicted);

[0182] The computer system (1400) may also include human-accessible storage devices and their associated media: for example, optical media including CD / DVD ROM / RW (1420) with CD / DVD etc. media (1421), thumb drives (1422), removable hard drives or solid-state drives (1423), traditional magnetic media such as tapes and floppy disks (not shown), dedicated ROM / ASIC / PLD based devices such as security dongles (not shown), etc.

[0183] Those skilled in the art should also understand that the term "computer-readable media" used in connection with the presently disclosed subject matter does not encompass transmission media, carrier waves, or other transitory signals.

[0184] The computer system (1400) may also include an interface to one or more communication networks. The network may be, for example, a wireless network, a wired network, an optical network. The network may further be a local network, a wide area network, a metropolitan area network, a vehicle and industrial network, a real-time network, a delay-tolerant network, etc. Examples of networks include local area networks such as Ethernet, wireless LANs, cellular networks including GSM, 3G, 4G, 5G, LTE, etc., television wired or wireless wide area digital networks including cable television, satellite television, and terrestrial broadcast television, vehicle and industrial television including CANBus, etc. Some networks typically require an external network interface adapter connected to some universal data port or peripheral bus (1449) (e.g., a USB port of the computer system (1400)); as described below, other network interfaces are typically integrated into the kernel of the computer system (1400) by connecting to the system bus (e.g., connected to an Ethernet interface in a PC computer system or connected to a cellular network interface in a smartphone computer system). The computer system (1400) can use any of these networks to communicate with other entities. Such communications may be one-way receive only (e.g., broadcast television), one-way send only (e.g., a CANbus connected to certain CANbus devices), or bidirectional, for example, using a LAN or WAN digital network to connect to other computer systems. As described above, certain protocols and protocol stacks may be used on each of those networks and network interfaces.

[0185] The above-mentioned human-machine interface device, human-machine accessible storage device, and network interface may be attached to the kernel ( 1440 ) of the computer system ( 1400 ).

[0186] The core (1440) may include one or more central processing units (CPUs) (1441), graphics processing units (GPUs) (1442), dedicated programmable processing units in the form of field programmable gate arrays (FPGAs) (1443), hardware accelerators (1444) for certain tasks, etc. These devices, as well as read-only memory (ROM) (1445), random access memory (1446), internal mass storage (1447) such as internal non-user accessible hard drives, SSDs, etc., may be connected via a system bus (1448). In some computer systems, the system bus (1448) may be accessed in the form of one or more physical plugs to enable expansion by additional CPUs, GPUs, etc. Peripheral devices may be connected directly to the core's system bus (1448) or connected to the core's system bus (1448) via a peripheral bus (1449). The architecture of the peripheral bus includes PCI, USB, etc.

[0187] The CPU (1441), GPU (1442), FPGA (1443) and accelerator (1444) can execute certain instructions, which can be combined to constitute the above-mentioned computer code. The computer code can be stored in ROM (1445) or RAM (1446). Transition data can also be stored in RAM (1446), while permanent data can be stored, for example, in internal mass storage (1447). Fast storage and retrieval to any storage device can be performed by using a cache, which can be closely associated with the following: one or more CPUs (1441), GPUs (1442), mass storage (1447), ROM (1445), RAM (1446), etc.

[0188] The computer readable medium may have thereon computer codes for performing various computer-implemented operations. The medium and computer codes may be those specially designed and constructed for the purposes of the present disclosure, or the medium and computer codes may be of a type well known and available to those skilled in the art of computer software.

[0189] As a non-limiting example, a computer system having an architecture (1400), particularly a kernel (1440), can provide functionality due to one or more processors (including CPUs, GPUs, FPGAs, accelerators, etc.) executing software contained in one or more tangible computer-readable media. Such computer-readable media can be media associated with user-accessible mass storage as described above, as well as memories of certain non-temporary kernels (1440), such as kernel internal mass storage (1447) or ROM (1445). Software implementing various embodiments of the present application can be stored in such devices and executed by the kernel (1440). Depending on specific needs, the computer-readable medium may include one or more storage devices or chips. The software can cause the kernel (1440), particularly the processors therein (including CPUs, GPUs, FPGAs, etc.), to perform specific processes or specific parts of specific processes described herein, including defining data structures (1446) stored in RAM and modifying such data structures according to processes defined by the software. Additionally or alternatively, the computer system may provide functionality due to logic hardwired or otherwise embodied in circuitry (e.g., accelerator (1444)) that may replace software or operate in conjunction with software to perform a particular process or a particular portion of a particular process described herein. Where appropriate, references to portions of software may include logic and vice versa. Where appropriate, references to portions of computer-readable media may include circuitry (e.g., integrated circuits (ICs)) storing software for execution, circuitry embodying logic for execution, or both. The present application includes any suitable combination of hardware and software.

[0190] Appendix A: Abbreviations

[0191] JEM: Joint Exploration Model

[0192] VVC: Next Generation Video Coding

[0193] BMS: Benchmark Set

[0194] HEVC: High Efficiency Video Coding

[0195] SEI: Supplemental Enhancement Information

[0196] VUI: Video Availability Information

[0197] GOP: Group of Pictures

[0198] TU: Transform Unit

[0199] PU: prediction unit

[0200] CTU: Coding Tree Unit

[0201] CTB: Coding Tree Block

[0202] PB: prediction block

[0203] HRD: Hypothetical Reference Decoder

[0204] SNR: Signal to Noise Ratio

[0205] CPU: Central Processing Unit

[0206] GPU: Graphics Processing Unit

[0207] CRT: cathode ray tube

[0208] LCD: Liquid Crystal Display

[0209] OLED: Organic Light Emitting Diode

[0210] CD: compact disc

[0211] DVD: Digital Video Disc

[0212] ROM: Read Only Memory

[0213] RAM: Random Access Memory

[0214] ASIC: Application-Specific Integrated Circuit

[0215] PLD: Programmable Logic Device

[0216] LAN: Local Area Network

[0217] GSM: Global System for Mobile Communications

[0218] LTE: Long Term Evolution

[0219] CANBus: Controller Area Network Bus

[0220] USB: Universal Serial Bus

[0221] PCI: Peripheral Component Interconnect

[0222] FPGA: Field Programmable Gate Array

[0223] SSD: Solid State Drive

[0224] IC: Integrated Circuit

[0225] CU: Coding Unit

[0226] Although the present application has described a number of exemplary embodiments, there are modifications, permutations, and various replacement equivalents that fall within the scope of the present application. Therefore, it should be understood that those skilled in the art will be able to design many systems and methods that, although not explicitly shown or described herein, embody the principles of the present application and therefore fall within the spirit and scope of the present application.

Claims

1. A video decoding method, characterized in that: The method comprises: decoding prediction information for a first block from an encoded video bitstream, the first block being a non-square block, and the prediction information for the first block indicating a first set of intra-prediction modes associated with the non-square block, the first set of intra-prediction modes comprising at least one wide-angle intra-prediction mode; Wherein, nWidth is defined as the width of the first block, nHeight is the height of the first block, 65 conventional intra prediction directions are used for intra prediction of the square block, the at least one wide-angle intra prediction mode is obtained by deleting some conventional intra prediction modes from the conventional intra prediction modes associated with the square block, and adding the same number of the wide-angle intra prediction modes to a set of new intra prediction modes for the rectangular block, the number of which depends on the aspect ratio of the first block, including: When nWidth is greater than nHeight but less than twice of nHeight, deleting the six regular intra prediction modes including mode 2 to mode 7, and combining the six wide-angle intra prediction modes including mode 67 to mode 72 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or When nWidth is equal to or greater than four times of nHeight, deleting the 10 regular intra prediction modes including mode 2 to mode 11, and combining the 10 wide-angle intra prediction modes including mode 67 to mode 76 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or When nHeight is greater than nWidth but less than twice of nWidth, deleting the six regular intra prediction modes including mode 61 to mode 66, and combining the six wide-angle intra prediction modes of mode -1 to mode -6 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or When nHeight is equal to or greater than four times of nWidth, the 10 regular intra-frame prediction modes including mode 57 to mode 66 are deleted, and the 10 wide-angle intra-frame prediction modes including mode -1 to mode -10 are combined with the remaining regular intra-frame prediction modes to form a new set of intra-frame prediction modes for the block.

2. The method according to claim 1, characterized in that The deleted regular intra prediction mode is not included in the first set of intra prediction modes.

3. The method according to claim 1, characterized in that: The wide-angle intra prediction mode is not included in a normal intra prediction mode for the square block.

4. The method according to claim 1, characterized in that: Also includes: Calculating the aspect ratio of the first block; as well as determining a second number of the regular intra prediction modes to delete based on an aspect ratio of the first block, The second number of regular intra-frame prediction modes is deleted from the regular intra-frame prediction mode, and the first number of wide-angle intra-frame prediction modes is added to the remaining modes of the regular intra-frame prediction mode to form the first group of intra-frame prediction modes, and the first number is equal to the second number.

5. The method according to claim 1, characterized in that The number of regular intra prediction modes is 65, corresponding to 65 regular intra prediction directions.

6. The method according to claim 5, characterized in that When the width of the first block is greater than the height, deleting a second number of normal intra prediction modes from the lower left direction of the normal intra prediction direction, and adding a corresponding number of wide-angle intra prediction modes from the upper right direction of the normal intra prediction direction, to obtain the first group of intra prediction modes; or When the height of the first block is greater than the width, the second number of intra-frame prediction modes are deleted from the upper right direction of the normal intra-frame prediction direction, and a corresponding number of the wide-angle intra-frame prediction modes are added from the lower left direction of the normal intra-frame prediction direction to obtain the first group of intra-frame prediction modes.

7. The method according to any one of claims 1 to 6, characterized in that: When nWidth is greater than nHeight but less than twice nHeight, and the index value of the regular intra-frame prediction mode is greater than or equal to 2 and less than 8, or when nWidth is equal to or greater than four times nHeight, and the index value of the regular intra-frame prediction mode is greater than or equal to 2 and less than 12, the regular intra-frame prediction mode is deleted, and the index value of the regular intra-frame prediction mode is increased by 65 and modified to the index value of the wide-angle intra-frame prediction mode.

8. The method according to any one of claims 1 to 6, characterized in that: include: When nHeight is greater than nWidth but less than twice nWidth, and the index value of the regular intra-frame prediction mode is greater than or equal to 61 and less than 67, or when nHeight is equal to or greater than four times nWidth, and the index value of the regular intra-frame prediction mode is greater than or equal to 57 and less than 67, the regular intra-frame prediction mode is deleted, and the index value of the regular intra-frame prediction mode is modified by subtracting 67 from the index value of the wide-angle intra-frame prediction mode.

9. A video decoding device, characterized in that: The device comprises: A processing circuit, wherein the processing circuit is configured to execute the decoding method according to any one of claims 1 to 8.

10. A video encoding method, characterized in that: The method comprises: Receive the first block; encoding prediction information for the first block into a video bitstream, wherein the first block is a non-square block, and the prediction information for the first block indicates that a first set of intra-prediction modes associated with the non-square block includes at least one wide-angle intra-prediction mode; Wherein, nWidth is defined as the width of the first block, nHeight is the height of the first block, 65 conventional intra prediction directions are used for intra prediction of the square block, some conventional intra prediction modes are deleted from the conventional intra prediction modes associated with the square block, and the same number of the wide-angle intra prediction modes are added to a set of new intra prediction modes for the rectangular block to obtain at least one wide-angle intra prediction mode, the number of which depends on the aspect ratio of the first block: When nWidth is greater than nHeight but less than or equal to twice of nHeight, deleting the six regular intra prediction modes including mode 2 to mode 7, and combining the six wide-angle intra prediction modes including mode 67 to mode 72 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or When nWidth is equal to or greater than four times of nHeight, deleting the 10 regular intra prediction modes including modes 2 to 11, and combining the 10 wide-angle intra prediction modes including modes 67 to 76 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or When nHeight is greater than nWidth but less than twice of nWidth, deleting the six regular intra prediction modes including mode 61 to mode 66, and combining the six wide-angle intra prediction modes of mode -1 to mode -6 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or When nHeight is equal to or greater than four times of nWidth, the 10 regular intra-frame prediction modes including mode 57 to mode 66 are deleted, and the 10 wide-angle intra-frame prediction modes including mode -1 to mode -10 are combined with the remaining regular intra-frame prediction modes to form a new set of intra-frame prediction modes for the block.

11. A video encoding device, characterized in that: The device comprises: an encoding module configured to receive a first block; encode prediction information of the first block into a video bitstream, wherein the first block is a non-square block, and the prediction information of the first block indicates a first set of intra-frame prediction modes associated with the non-square block, and the first set of intra-frame prediction modes includes at least one wide-angle intra-frame prediction mode; Wherein, nWidth is defined as the width of the first block, nHeight is the height of the first block, 65 conventional intra prediction directions are used for intra prediction of the square block, and the encoding module is specifically configured to delete some conventional intra prediction modes from the conventional intra prediction modes associated with the square block, and add the same number of the wide-angle intra prediction modes to a set of new intra prediction modes for the rectangular block to obtain at least one wide-angle intra prediction mode, and the number depends on the aspect ratio of the first block in the following manner: When nWidth is greater than nHeight but less than or equal to twice of nHeight, deleting the six regular intra prediction modes including mode 2 to mode 7, and combining the six wide-angle intra prediction modes including mode 67 to mode 72 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or When nWidth is equal to or greater than four times of nHeight, deleting the 10 regular intra prediction modes including modes 2 to 11, and combining the 10 wide-angle intra prediction modes including modes 67 to 76 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or When nHeight is greater than nWidth but less than twice of nWidth, deleting the six regular intra prediction modes including mode 61 to mode 66, and combining the six wide-angle intra prediction modes of mode -1 to mode -6 with the remaining regular intra prediction modes to form a set of new intra prediction modes for the block; or When nHeight is equal to or greater than four times of nWidth, the 10 regular intra-frame prediction modes including mode 57 to mode 66 are deleted, and the 10 wide-angle intra-frame prediction modes including mode -1 to mode -10 are combined with the remaining regular intra-frame prediction modes to form a new set of intra-frame prediction modes for the block.

12. A non-transitory computer-readable medium, characterized in that Computer executable instructions are stored, and when the computer executable instructions are executed by a computer to perform video encoding and decoding, the computer is caused to execute the method according to any one of claims 1 to 8 or claim 10.

13. A computer device, characterized in that: The computer device comprises: A memory for storing computer executable instructions; A processor, configured to implement the method according to any one of claims 1 to 8 or claim 10 when executing computer executable instructions or computer programs stored in the memory.

14. A method for processing a video bitstream, characterized in that: The video bit stream is decoded based on the video decoding method according to any one of claims 1 to 8, or the video bit stream is generated according to the video encoding method according to claim 10.

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