A method and related device for video encoding

Abstract

A method and a related device for video encoding are disclosed. The method includes: determining an intra-frame prediction mode for encoding a current block, the current block being a non-square block; determining an intra-frame prediction angle corresponding to the intra-frame prediction mode based on a predetermined correspondence relationship, the predetermined correspondence relationship being a correspondence relationship between multiple intra-frame prediction angles and multiple intra-frame prediction modes; and generating prediction information indicating the determined intra-frame prediction mode.

Description

[0001] Cross-references

[0002] This application claims priority to U.S. Patent Application No. 16 / 147,313, filed on September 28, 2018, entitled “METHOD AND APPARATUS FOR VIDEOCODING,” now U.S. Patent No. 10,284,844, which claims priority to U.S. Provisional Application No. 62 / 711,390, filed on July 27, 2018, entitled “Improvements on Wide-Angle Intra Prediction,” and U.S. Provisional Application No. 62 / 693,050, filed on July 2, 2018, entitled “Methods and Apparatus for Wide Angular Intra Prediction in Video Compression,” the entire contents of each of the above applications are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to video processing technology, and more particularly to a method and a related device for performing video decoding in a video decoder. Background Art

[0004] The background description provided herein is for the purpose of generally presenting the context of the present disclosure. To the extent the work described in this background section, the work of the presently named inventors and aspects of the description that may not otherwise be qualified as prior art at the time of filing are neither explicitly nor implicitly admitted as prior art to the present disclosure.

[0005] Video encoding and decoding can be performed using inter-picture prediction with motion compensation. Uncompressed digital video can include a series of pictures, each of which has a spatial size of, for example, 1920×1080 luma samples and associated chroma samples. This series of pictures can have a fixed or variable picture rate (also informally referred to as a frame rate), such as 60 pictures per second or 60Hz. Uncompressed video has significant bit rate requirements. For example, 1080p60 4:2:0 video with 8 bits per sample (1920×1080 luma sample resolution at 60Hz frame rate) requires a bandwidth close to 1.5Gbit / s. One hour of such video requires more than 600GByte of storage space.

[0006] One purpose of video encoding and decoding can be to reduce redundancy in the input video signal by compression. Compression can help reduce the bandwidth or storage space requirements mentioned above, in some cases by two orders of magnitude or more. Both lossless and lossy compression and combinations of the two can be used. Lossless compression refers to a technique that can reconstruct an exact copy of the original signal based on the compressed original signal. When lossy compression is used, the reconstructed signal may be different from 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 distortion that can be tolerated depends on the application; for example, users of certain consumer streaming applications may tolerate higher distortion than users of television distribution applications. The achievable compression ratio can reflect that higher allowable / tolerable distortion can produce higher compression ratios.

[0007] Video encoders and decoders may utilize techniques in several general categories including, for example, motion compensation, transforms, quantization, and entropy coding.

[0008] Video codec techniques may include techniques known as intra-frame coding. In intra-frame 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 sample blocks. When all sample blocks are encoded in intra-frame mode, the picture may be an intra-frame picture. Intra-frame pictures and their derivatives (e.g., independent decoder refresh pictures) may be used to reset decoder states, and may therefore be used as the first picture in an encoded video bitstream and video session or as a still image. Transforms may be applied to samples of intra-frame blocks, and transform coefficients may be quantized before entropy coding. Intra-frame prediction may be a technique for minimizing sample values ​​in a pre-transform domain. In some cases, the smaller the DC value after the transform, and the smaller the AC coefficient, the fewer bits are required to represent the block after entropy coding at a given quantization step size.

[0009] Conventional intra-frame coding, such as known from, for example, the MPEG-2 generation of coding techniques, does not use intra-frame prediction. However, some newer video compression techniques include techniques that attempt, for example, from metadata and / or surrounding sample data 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, in at least some cases, intra-frame prediction uses only reference data from the current picture being reconstructed, and not reference data from reference pictures.

[0010] There can be many different forms of intra-frame prediction. When more than one such technique can be used in a given video coding technique, the technique used can be encoded in an intra-frame prediction mode. 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 affect the coding efficiency gain obtained through intra-frame prediction, and entropy coding techniques can also be used to convert the codewords into a bitstream.

[0011] Specific modes of intra prediction were introduced with H.264, refined in H.265, and further refined in newer coding techniques such as the Joint Exploration Model (JEM), Versatile Video Coding (VVC), and Benchmark Sets (BMS). Neighboring sample values ​​belonging to samples that are already available can be used to form a prediction block. Sample values ​​of neighboring samples are copied into the prediction block according to the direction. A reference to the direction being used can be encoded in the bitstream, or it can be predicted itself.

[0012] However, current intra prediction techniques are not efficient for processing non-square blocks. Summary of the invention

[0013] Aspects of the present disclosure provide methods and related apparatus for video encoding.In some examples, an apparatus includes receiving circuitry and processing circuitry.

[0014] One aspect of the present disclosure provides a method for video encoding. The method includes: determining an intra-frame prediction mode for encoding a current block, the current block being a non-square block; determining an intra-frame prediction angle corresponding to the intra-frame prediction mode based on a predetermined correspondence, the predetermined correspondence being a correspondence between multiple intra-frame prediction angles and multiple intra-frame prediction modes; and generating prediction information indicating the determined intra-frame prediction mode, wherein the current block has a width W and a height H; among the 67 intra-frame prediction modes, when W / H==1 / 2, the determined intra-frame prediction mode includes a first wide-angle prediction mode, which is obtained by replacing conventional angle intra-frame prediction modes 61, 62, 63, 64, 65, and 66; when W / H==2, the determined intra-frame prediction mode includes a second wide-angle prediction mode, which is obtained by replacing conventional angle intra-frame prediction modes 2, 3, 4, 5, 6, and 7;

[0015] The first wide-angle prediction mode exceeds a diagonal mode in a lower left direction of the current block, and the second wide-angle prediction mode exceeds a diagonal mode in an upper right direction of the current block.

[0016] Another aspect of the present disclosure provides a video encoder. The encoder includes a processing circuit configured to perform the following operations: determine an intra-frame prediction mode for encoding a current block, wherein the current block is a non-square block; determine an intra-frame prediction angle corresponding to the intra-frame prediction mode based on a predetermined correspondence relationship, wherein the predetermined correspondence relationship is a correspondence relationship between multiple intra-frame prediction angles and multiple intra-frame prediction modes; and generate prediction information indicating the determined intra-frame prediction mode, wherein the current block has a width W and a height H; in 67 intra-frame prediction modes, when W / H==1 / 2, the determined intra-frame The prediction mode includes a first wide-angle prediction mode, which is obtained by replacing the conventional angle intra-frame prediction modes 61, 62, 63, 64, 65 and 66; when W / H==2, the determined intra-frame prediction mode includes a second wide-angle prediction mode, which is obtained by replacing the conventional angle intra-frame prediction modes 2, 3, 4, 5, 6 and 7; wherein the first wide-angle prediction mode exceeds the lower left diagonal mode of the current block, and the second wide-angle prediction mode exceeds the upper right diagonal mode of the current block.

[0017] Another aspect of the present disclosure provides an apparatus for performing video encoding in a video encoder, the apparatus comprising a determining module, a corresponding module, and a generating module:

[0018] The determination module is configured to determine an intra-frame prediction mode for encoding a current block, the current block is a non-square block, and the intra-frame prediction angle exceeds a lower left diagonal mode or exceeds an upper right diagonal mode;

[0019] The corresponding module is configured to determine the intra prediction angle corresponding to the intra prediction mode based on a predetermined corresponding relationship, wherein the predetermined corresponding relationship is a corresponding relationship between a plurality of intra prediction angles and a plurality of intra prediction modes; and

[0020] The generating module is configured to generate prediction information indicating the determined intra prediction mode,

[0021] Wherein, the current block has a width W and a height H;

[0022] Among the 67 intra prediction modes, when W / H==1 / 2, the determined intra prediction mode includes a first wide-angle prediction mode, which is obtained based on the replacement of the normal angle intra prediction modes 61, 62, 63, 64, 65 and 66;

[0023] When W / H==2, the determined intra prediction mode includes a second wide-angle prediction mode, which is obtained based on the normal angle intra prediction modes 2, 3, 4, 5, 6 and 7 being replaced;

[0024] The first wide-angle prediction mode exceeds a diagonal mode in a lower left direction of the current block, and the second wide-angle prediction mode exceeds a diagonal mode in an upper right direction of the current block.

[0025] Aspects of the present disclosure also provide a non-transitory computer-readable medium storing instructions that, when executed by a computer for video encoding, cause the computer to perform the above-described method for video encoding.

[0026] Another aspect of the present disclosure provides a computer device, the device comprising a processor and a memory:

[0027] The memory is used to store program code and transmit the program code to the processor;

[0028] The processor is used to execute the above-mentioned method for video encoding according to the instructions in the program code.

[0029] It can be seen from the above technical solution that it can be applied to reconstruct at least one sample in a non-square block and a square block using the relationship between the intra-frame prediction mode and the intra-frame prediction angle. The non-square block uses the wide-angle mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Additional features, properties, and various advantages of the disclosed subject matter will become more apparent from the following detailed description and accompanying drawings, in which:

[0031] Figure 1 is a schematic illustration of an exemplary intra prediction mode;

[0032] Figure 2 is another illustration of an exemplary intra prediction mode;

[0033] Figure 3 is a schematic illustration of a simplified block diagram of a communication system according to an embodiment;

[0034] Figure 4 is a schematic illustration of a simplified block diagram of a communication system according to another embodiment;

[0035] Figure 5 is a schematic illustration of a simplified block diagram of a decoder according to an embodiment;

[0036] Figure 6 is a schematic illustration of a simplified block diagram of an encoder according to another embodiment;

[0037] Figure 7 is a block diagram of an encoder according to another embodiment;

[0038] Figure 8 is a block diagram of a decoder according to another embodiment;

[0039] Fig. 9 is a diagram showing an exemplary wide-angle mode;

[0040] Fig.10 is a diagram showing an exemplary intra prediction angle definition;

[0041] Fig.11A and Fig. 11B is a diagram of a method according to an embodiment of the present invention;

[0042] Fig.12 is a diagram showing predicted angles within a diagonal direction and predicted angles beyond the diagonal direction;

[0043] Fig.13 is a schematic illustration of a computer system according to an embodiment. DETAILED DESCRIPTION

[0044] For the Chinese meanings and English full names of the English abbreviations involved in this disclosure, please refer to Appendix A attached at the end of the specification.

[0045] Reference Figure 1 , depicted at the bottom right is a subset of 9 prediction directions known from the 35 possible prediction directions of H.265. The point (101) where the arrows converge represents the sample being predicted. The arrows represent the direction in which the sample is predicted. For example, arrow (102) indicates that sample (101) is predicted from one or more samples at an angle of 45 degrees to the horizontal to the upper right. Similarly, arrow (103) indicates that sample (101) is predicted from one or more samples at an angle of 22.5 degrees to the horizontal to the lower left of sample (101).

[0046] Still refer to Figure 1 , a square block (104) of 4×4 samples is depicted at the top left (indicated by a bold dashed line). The square block (104) includes 16 samples, each of which is labeled with "S", the position of the sample in the Y dimension (e.g., row index), and the position of the sample 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 both the Y and X dimensions in block (104). Since the size of block (104) is 4×4 samples, sample S44 is at the bottom right. Reference samples are also shown, which follow a similar numbering scheme. The reference samples are labeled with R, the Y position (e.g., row index) and the X position (column index) of the reference sample relative to block (104). In both H.264 and H.265, the prediction samples are adjacent to the block being reconstructed; therefore, there is no need to use negative values.

[0047] Intra-picture prediction can be achieved by appropriately copying reference sample values ​​from neighboring samples according to a signaled prediction direction. For example, assume that the encoded video bitstream includes signaling for the block indicating a prediction direction consistent with arrow (102) - that is, the samples are predicted from one or more prediction samples to the upper right at a 45 degree angle to the horizontal. In this case, samples S41, S32, S23, and S14 are predicted from the same sample R05. Sample S44 is then predicted from R08.

[0048] In some cases, the values ​​of multiple reference samples may be combined, such as by interpolation, in order to compute a reference sample; particularly if the directions do not divide evenly at 45 degrees.

[0049] As video coding technology has developed, the number of possible directions has increased. In H.264 (2003), 9 different directions could be represented. This increased to 33 in H.265 (2013), and JEM / VVC / BMS can support up to 65 directions when disclosed. Experiments have been conducted to identify the most likely directions, and certain techniques in entropy coding are used to represent these possible directions with a smaller number of bits, thereby accepting specific penalties for less likely directions. In addition, the direction itself can sometimes be predicted from the neighboring directions used in adjacent decoded blocks.

[0050] Figure 2 is a schematic diagram 201 depicting 67 intra prediction modes according to JEM, for illustrating the increasing number of prediction directions over time.

[0051] The mapping of the intra-prediction direction bits representing directions in the coded video bitstream may vary from one video coding technique to another; and may vary, for example, from a simple direct mapping of prediction directions to intra-prediction modes to codewords to complex adaptive schemes involving most probable modes and similar techniques. Those skilled in the art will readily be familiar with these techniques. However, in all cases, there may be certain directions that are statistically less likely to appear in the video content than certain other directions. Since the goal of video compression is to reduce redundancy, in well-functioning video coding techniques, the number of bits used to represent those less likely directions is greater than the number of bits used to represent more likely directions.

[0052] Figure 3 3 shows a simplified block diagram of a communication system 300 according to an embodiment of the present disclosure. The communication system 300 includes a plurality of terminal devices that can communicate with each other 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 the example, the first pair of terminal devices 310 and 320 perform unidirectional data transmission. For example, the terminal device 310 can encode video data (e.g., a video picture stream captured by the terminal device 310) for transmission to another terminal device 320 via the network 350. The encoded video data can be transmitted in the form of one or more encoded video bitstreams. The terminal device 320 can receive the encoded video data from the network 350, decode the encoded video data to restore the video picture, and display the video picture according to the restored video data. Unidirectional data transmission may be common in media service applications, etc.

[0053] In another example, the communication system 300 includes a second pair of terminal devices 330 and 340 that perform bidirectional transmission of encoded video data, which can occur, for example, during a video conference. For bidirectional data transmission, in an example, each of the terminal devices 330 and 340 can encode video data (e.g., a video picture stream captured by the terminal device) for transmission to the other of the terminal devices 330 and 340 via the network 350. Each of the terminal devices 330 and 340 can also receive the encoded video data transmitted by the other of the terminal devices 330 and 340, and can decode the encoded video data to restore the video picture, and can display the video picture at an accessible display device based on the restored video data.

[0054] exist Figure 3 In the example, terminal devices 310, 320, 330 and 340 can be shown as servers, personal computers and smart phones, but the principles of the present disclosure may not be limited thereto. The embodiments of the present disclosure are applicable to laptop computers, tablet computers, media players and / or special video conferencing equipment. Network 350 represents any number of networks that transmit encoded video data between terminal devices 310, 320, 330 and 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 include telecommunication networks, local area networks, wide area networks and / or the Internet. For the purpose of this discussion, unless otherwise specified hereinafter, the architecture and topology of network 350 may be unimportant for the operation of the present disclosure.

[0055] As examples of applications of the disclosed subject matter, Figure 4 The placement of the video encoder and video decoder in a streaming environment is shown. The disclosed subject matter can be 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.

[0056] The streaming system may include a capture subsystem 413, which may include a video source 401, such as a digital camera, which creates, for example, an uncompressed video picture stream 402. In an example, the video picture stream 402 includes samples taken by the digital camera. The video picture stream 402 is depicted as thick lines to emphasize the high amount of data compared to the encoded video data 404 (or encoded video bitstream), which can be processed by an electronic device 420 including a video encoder 403 coupled to the video source 401. The video encoder 403 may include hardware, software, or a combination thereof to implement or implement various aspects of the disclosed subject matter as described in more detail below. The encoded video data 404 (or encoded video bitstream 404) is depicted as thin lines to emphasize the lower amount of data compared to the video picture stream 402, which can be stored on a streaming server 405 for future use. One or more streaming client subsystems (e.g., Figure 4 The client subsystems 406 and 408 in the video transmission system 405 can access the streaming server 405 to retrieve the copies 407 and 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 creates an outgoing video picture stream 411 that can be presented on a display 412 (e.g., a display screen) or another rendering device (not depicted). In some streaming systems, the encoded video data 404, 407, and 409 (e.g., video bitstreams) can be encoded according to certain video encoding / compression standards. Examples of these standards include ITU-T H.265 Recommendation. In the example, the video coding standard under development is informally referred to as Versatile Video Coding or VVC. The disclosed subject matter can be used in the context of VVC.

[0057] Note that the electronic devices 420 and 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).

[0058] Figure 5 5 shows a block diagram of a video decoder 510 according to an embodiment of the present disclosure. The video decoder 510 may be included in an electronic device 530. The electronic device 530 may include a receiver 531 (eg, a receiving circuit). The video decoder 510 may be used to replace Figure 4 Video decoder 410 in the example.

[0059] Receiver 531 may receive one or more encoded video sequences to be decoded by 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 channel 501, which may be a hardware / software link to a storage device storing the encoded video data. Receiver 531 may receive the encoded video data as well as other data, such as encoded audio data and / or auxiliary data streams that may be forwarded to their respective use entities (not depicted). Receiver 531 may separate the encoded video sequence from the other data. To cope with network jitter, a buffer memory 515 may be coupled between receiver 531 and entropy decoder / parser 520 (hereinafter referred to as "parser 520"). In some applications, buffer memory 515 is part of video decoder 510. In other applications, buffer memory 515 may be external to video decoder 510 (not depicted). In still other applications, there may be a buffer memory (not depicted) external to the video decoder 510 to, for example, cope with network jitter, and furthermore there may be another buffer memory 515 internal to the video decoder 510 to, for example, handle playout timing. When the receiver 531 receives data from a store / forward device with sufficient bandwidth and controllability or from an isochronous network, the buffer memory 515 may not be needed, or the buffer memory 515 may be small. In order to use a packet network such as the Internet as much as possible, a buffer memory 515 may be needed, which may be relatively large and may advantageously have an adaptive size, and may be at least partially implemented in an operating system or similar element (not depicted) external to the video decoder 510.

[0060] The video decoder 510 may include a parser 520 to reconstruct symbols 521 from the encoded video sequence. The categories of these symbols include information for managing the operation of the video decoder 510 and information that may be used to control a rendering device such as a rendering device 512 (e.g., a display screen) that is not part of the electronic device 530 but can be coupled to the electronic device 530, such as Figure 5As shown. The control information for the presentation device may be in the form of a supplemental enhancement information (SEI message) or a video usability information (VUI) parameter set fragment (not depicted). The parser 520 may parse / entropy decode the received coded video sequence. The coding 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, etc. The parser 520 may extract a subgroup parameter set for at least one subgroup of the pixel subgroups 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 (Group of Pictures, GOP), a picture, a tile, a slice, a macroblock, a coding unit (Coding Unit, CU), a block, a transform unit (TransformUnit, TU), a prediction unit (Prediction Unit, PU), etc. The parser 520 may also extract information such as transform coefficients, quantizer parameter values, motion vectors, etc. from the coded video sequence.

[0061] Parser 520 may perform entropy decoding / parsing operations on the video sequence received from buffer memory 515 , thereby creating symbols 521 .

[0062] Depending on the type of the coded video picture or part of the coded video picture (such as: inter-frame picture and intra-frame picture, inter-frame block and intra-frame block) and other factors, the reconstruction of the symbol 521 may involve multiple different units. Which units are involved and how they are involved can be controlled by sub-group control information parsed from the coded video sequence by the parser 520. For the sake of brevity, such sub-group control information flow between the parser 520 and the following multiple units is not described.

[0063] In addition to the functional blocks already mentioned, the video decoder 510 can be conceptually subdivided into several functional units as described below. In actual implementations that operate 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, it is appropriate to conceptually subdivide into the following functional units.

[0064] 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, as well as control information including which transform method to use, block size, quantization factor, quantization scaling matrix, etc. The sealer / inverse transform unit 551 may output a block including sample values ​​that may be input into an aggregator 555.

[0065] In some cases, the output samples of the sealer / 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 the intra-picture prediction unit 552. In some cases, the intra-picture prediction unit 552 uses surrounding reconstructed information taken from the current picture buffer 558 to generate a block of the same size and shape as the block under reconstruction. 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 already generated by the intra-prediction unit 552 to the output sample information provided by the sealer / inverse transform unit 551 on a per-sample basis.

[0066] In other cases, the output samples of the scaler / inverse transform unit 551 may belong to a block that has been inter-coded and possibly motion compensated. In this case, the motion compensated prediction unit 553 may access the reference picture memory 557 to retrieve samples for prediction. After motion compensation of the retrieved samples according to the symbols 521 belonging to the block, these samples may be added by the aggregator 555 to the output of the scaler / inverse transform unit 551 (in this case referred to as residual samples or residual signals), thereby generating output sample information. The address within the reference picture memory 557 from which the motion compensated prediction unit 553 retrieves the predicted samples may be controlled by a motion vector, which may be available 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 ​​retrieved from the reference picture memory 557 when using sub-sample accurate motion vectors, motion vector prediction mechanisms, etc.

[0067] In other cases, the output samples of the scaler / inverse transform unit 551 may belong to an inter-frame coded and possibly motion compensated block. In this case, the motion compensated prediction unit 553 may access the reference picture memory 557 to obtain samples for prediction. After motion compensation of the obtained samples 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, thereby generating output sample information. The address within the reference picture memory 557 from which the motion compensated prediction unit 553 obtains the predicted samples may be controlled by a motion vector, which can be used by 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 ​​obtained from the reference picture memory 557 when using sub-sample accurate motion vectors, motion vector prediction mechanisms, etc.

[0068] 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 a coded video bitstream) and available to the loop filter unit 556 as symbols 521 from the parser 520, but 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, and to previously reconstructed and loop filtered sample values.

[0069] The output of the loop filter unit 556 may be a sample stream that may be output to the rendering device 512 and stored in the reference picture memory 557 for use in future inter-picture prediction.

[0070] Certain coded pictures, once fully reconstructed, may be used as reference pictures for future predictions. For example, once a coded picture corresponding to a current picture is fully reconstructed and the coded picture is identified as a reference picture (e.g., by parser 520), current picture buffer 558 may become part of reference picture memory 557, and a new current picture buffer may be reallocated before starting reconstruction of a subsequent coded picture.

[0071] The video decoder 510 may perform decoding operations according to a predetermined video compression technique in a standard such as ITU-T H.265 Recommendation. The encoded video sequence may conform to the syntax specified by the video compression technology or standard used in the sense that the encoded video sequence follows both the syntax of the video compression technology or standard and the profile recorded in the video compression technology or standard. Specifically, the profile may select certain tools from all the tools available in the video compression technology 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 technology or standard. In some cases, the hierarchy limits the maximum picture size, the maximum frame rate, the maximum reconstruction sample rate (measured in, for example, megasamples per second), the maximum reference picture size, etc. In some cases, the limits set by the hierarchy may be further defined by the Hypothetical Reference Decoder (HRD) specification and the metadata of the HRD buffer management signaled in the encoded video sequence.

[0072] 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.

[0073] Figure 6 603 according to an embodiment of the present disclosure. The video encoder 603 is included in an electronic device 620. The electronic device 620 includes a transmitter 640 (eg, a transmission circuit). The video encoder 603 may be used to replace Figure 4 Video encoder 403 in the example.

[0074] The video encoder 603 can obtain the video source 601 (not Figure 4 6. In another example, video source 601 is a part of electronic device 420, which may capture video images to be encoded by video encoder 603. In another example, video source 601 is a part of electronic device 620.

[0075] The video source 601 can provide a source video sequence to be encoded by the video encoder 603 in the form of a digital video sample stream, which can have any suitable bit depth (e.g., 8 bits, 10 bits, 12 bits ...), any color space (e.g., BT.601Y CrCB, RGB ...) and any suitable sampling structure (e.g., YCrCb 4:2:0, Y CrCb 4:4:4). In a media service system, the video source 601 can be a storage device that stores previously prepared videos. In a video conferencing system, the video source 601 can be a camera that captures local image information as a video sequence. The video data can be provided as multiple separate pictures that are given motion when viewed in sequence. The picture itself can be organized as a spatial pixel array, wherein each pixel can include one or more samples, depending on the sampling structure, color space, etc. used. The relationship between pixels and samples can be easily understood by those skilled in the art. The following description focuses on samples.

[0076] According to an embodiment, the video encoder 603 can encode and compress the pictures of the source video sequence into an encoded video sequence 643 in real time or under any other time constraints required by the application. It is a function of the controller 650 to implement the appropriate encoding speed. In some embodiments, the controller 650 controls other functional units as described below and is functionally coupled to the other functional units. The coupling is not depicted for simplicity. The parameters set by the controller 650 may include rate control related parameters (picture skipping, quantizer, lambda value of rate distortion optimization technology...), picture size, picture group (GOP) layout, maximum motion vector search range, etc. The controller 650 can be configured to have other suitable functions that are related to the video encoder 603 optimized for a specific system design.

[0077] In some embodiments, the video encoder 603 is configured to operate in an encoding loop. As an oversimplified 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 the input picture to be encoded and the 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 how the (remote) decoder will also create sample data (because in the video compression technology considered in the disclosed subject matter, any compression between the symbols and the encoded video bitstream is lossless). This reconstructed sample stream (sample data) is input to the reference picture memory 634. Since the decoding of the symbol stream results in a bit-accurate result that is independent of the decoder location (local or remote), the contents of the reference picture memory 634 are also bit-accurate 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 prediction during decoding. This basic principle of reference picture synchronization (and the drift caused when synchronization cannot be maintained, for example due to channel errors) is also used in some related technologies.

[0078] The operation of the "local" decoder 633 can be combined with the above Figure 5 The operation of the "remote" decoder described in detail is the same as that of the video decoder 610. However, reference will be made briefly to Figure 5 , when symbols are available and the entropy encoder 545 and the 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 does not need to be fully implemented in the local decoder 633.

[0079] At this point, it can be observed that any decoder technology other than 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 decoder operation. Since encoder technology is mutually inverse to the decoder technology that has been fully described, the description of encoder technology can be simplified. A more detailed description is only required and provided in certain places below.

[0080] In some examples, during operation, source encoder 630 may perform motion compensated predictive coding, which predictively encodes an input picture with reference to one or more previously encoded pictures from a video sequence designated as “reference pictures.” In this manner, encoding engine 632 encodes the differences between pixel blocks of an input picture and pixel blocks of a reference picture that may be selected as a prediction reference for the input picture.

[0081] The local video decoder 633 can decode the encoded video data of the picture that can be designated as the reference picture based on the symbols created by the source encoder 630. The operation of the encoding engine 632 can advantageously be lossy processing. When the encoded video data can be decoded at the video decoder ( Figure 6 When decoded at a remote video decoder (not shown), the reconstructed video sequence may typically be a replica 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 copies of the reconstructed reference pictures that have common content (absent transmission errors) with the reconstructed reference pictures that the remote video decoder will obtain.

[0082] 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 a candidate reference pixel block) or certain metadata, such as reference picture motion vectors, block shapes, etc., that may be used as an appropriate prediction reference for the new picture. The predictor 635 may operate on a pixel block by pixel block basis to find an appropriate prediction reference. In some cases, the input picture may have a prediction reference taken from a plurality of reference pictures stored in the reference picture memory 634, as determined by the search results obtained by the predictor 635.

[0083] The controller 650 may manage encoding operations of the source encoder 630 , including, for example, setting of parameters and subgroup parameters for encoding video data.

[0084] The outputs of all the above functional units may be entropy encoded in the entropy encoder 645. The entropy encoder 645 converts the symbols generated by the various functional units into a coded video sequence by losslessly compressing the symbols according to techniques known to those skilled in the art, such as Huffman coding, variable length coding, arithmetic coding, etc.

[0085] Transmitter 640 may buffer the encoded video sequence created by entropy encoder 645 in preparation for transmission via communication channel 660, which may be a hardware / software link to a storage device where the encoded video data will be stored. Transmitter 640 may combine the encoded video data from video encoder 603 with other data to be transmitted, such as encoded audio data and / or auxiliary data streams (source not shown).

[0086] The controller 650 may manage the operation of the video encoder 603. During encoding, the controller 650 may assign a specific coded picture type to each coded picture, which may affect the coding techniques that may be applied to the corresponding picture. For example, a picture may generally be assigned one of the following picture types:

[0087] 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 for different types of intra pictures, including, for example, Independent Decoder Refresh ("IDR") pictures. Those skilled in the art are aware of these variations of I pictures and their corresponding applications and features.

[0088] A predictive picture (P picture) may be a picture that may 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.

[0089] Bi-predictive pictures (B pictures), which can be pictures that can be encoded and decoded using intra-frame prediction or inter-frame prediction, which uses up to two motion vectors and reference indices to predict the sample values ​​of each block. Similarly, multi-predictive pictures can use more than two reference pictures and associated metadata for reconstruction of a single block.

[0090] The source picture may typically be spatially subdivided into a plurality of blocks of samples (e.g., blocks of 4×4, 8×8, 4×8, or 16×16 samples, respectively), and coded block by block. These blocks may be predictively coded with reference to other (already coded) blocks, which are determined according to the coding allocation applied to the corresponding picture of the block. For example, blocks of an I picture may be non-predictively coded, or may be predictively coded (spatial prediction or intra prediction) with reference to already coded blocks of the same picture. Pixel blocks of a P picture may be predictively coded with reference to one previously coded reference picture via spatial prediction or via temporal prediction. Blocks of a B picture may be predictively coded with reference to one or two previously coded reference pictures via spatial prediction or via temporal prediction.

[0091] 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 the operation of the video encoder 603, the video encoder 603 may perform various compression operations, including predictive encoding operations that exploit temporal and spatial redundancy in the input video sequence. Thus, the encoded video data may conform to the syntax specified by the video encoding technique or standard used.

[0092] In an embodiment, the transmitter 640 may transmit additional data along with the encoded video. The source encoder 630 may include such data as part of the encoded video sequence. The additional data may include temporal / spatial / SNR enhancement layers, other forms of redundant data such as redundant pictures and slices, supplemental enhancement information (SEI) messages, visual usability information (VUI) parameter set segments, etc.

[0093] Video can be captured as a temporal sequence of multiple source pictures (video pictures). Intra-picture prediction (often abbreviated as 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 (which is referred to as the current picture) is divided into blocks. When a block in the current picture is similar to a reference block in a reference picture that has been previously encoded in the video and is still buffered, the block in the current picture can 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 of using multiple reference pictures, the motion vector may have a third dimension that identifies the reference picture.

[0094] In some embodiments, a bidirectional prediction technique 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, respectively, in display order). 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. The block may be predicted by a combination of the first reference block and the second reference block.

[0095] In addition, merge mode techniques can be used in inter-picture prediction to improve coding efficiency.

[0096] According to some embodiments of the present disclosure, predictions such as inter-picture prediction and intra-picture prediction are performed in units of blocks. For example, according to the HEVC (High Efficiency Video Coding) 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)—a luminance CTB and two chrominance CTBs. Each CTU can be recursively split into one or more coding units (CUs) in 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 the prediction type for the CU, such as an inter-prediction type or an intra-prediction type. According to temporal and / or spatial predictability, a CU is split into one or more prediction units (PUs). Typically, each PU includes a luminance prediction block (PB) and two chrominance PBs. In an embodiment, the prediction operation in encoding (encoding / decoding) is performed in units of prediction blocks. Using a luma prediction block as an example of a prediction block, the prediction block includes a matrix of pixel values ​​(e.g., luma values), such as 8×8 pixels, 16×16 pixels, 8×16 pixels, 16×8 pixels, etc.

[0097] Figure 7 A diagram of a video encoder 703 according to another embodiment of the present disclosure is shown. The video encoder 703 is configured to receive a processed block (e.g., a predicted block) of sample values ​​within a current video picture in a sequence of video pictures and encode the processed block into an encoded picture that is part of an encoded video sequence. In an example, the video encoder 703 is used to replace Figure 4 Video encoder 403 in the example.

[0098] In the HEVC example, the video encoder 703 receives a matrix of sample values ​​for a processing block, such as a prediction block of 8×8 samples, etc. The video encoder 703 uses, for example, rate-distortion optimization to determine whether the processing block can be best encoded using an intra-frame mode, an inter-frame mode, or a bidirectional prediction mode. In the case where the processing block is to be encoded in an intra-frame mode, the video encoder 703 can encode the processing block into an encoded picture using an intra-frame prediction technique; and in the case where the processing block is to be encoded in an inter-frame mode or a bidirectional prediction mode, the video encoder 703 can encode the processing block into an encoded picture using an inter-frame prediction technique or a bidirectional prediction technique, respectively. In some video coding techniques, the merge mode can be an inter-frame picture prediction submode, in which a motion vector is derived from one or more motion vector predictors without the aid of an encoded motion vector component outside of the one or more motion vector predictors. In some other video coding techniques, there may be a motion vector component applicable to the subject block. In the example, the video encoder 703 includes other components, such as a mode decision module (not shown) for determining the mode of the processing block.

[0099] exist Figure 7 In the example of FIG. 1 , the video encoder 703 includes Figure 7 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 are shown coupled together.

[0100] 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.

[0101] The intra encoder 722 is configured to receive samples of a current block (e.g., a processing block), compare the block with encoded blocks in the same picture in some cases, generate quantization 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).

[0102] The general controller 721 is configured to determine the general control data and control other components of the video encoder 703 based on the general control data. In the 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 the 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 the intra prediction information and include the intra prediction information in the bitstream; and when the mode is the 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 include the inter prediction information in the bitstream.

[0103] The residual calculator 723 is configured to calculate the difference (residual data) between the received block and the prediction result selected from the intra encoder 722 or the inter encoder 730. The residual encoder 724 is configured to operate based on the residual data to encode the residual data to generate a transform coefficient. In an example, the residual encoder 724 is configured to convert the residual data in the frequency domain and generate a transform coefficient. The transform coefficient is then quantized to obtain a quantized transform coefficient.

[0104] The entropy encoder 725 is configured to format the bitstream to include the encoded blocks. The entropy encoder 725 is configured to include 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 (e.g., intra-frame prediction information or inter-frame prediction information), residual information, and other suitable information in the bitstream. Note that according to the disclosed subject matter, when the block is encoded in the merge sub-mode of the inter-frame mode or the bidirectional prediction mode, there is no residual information.

[0105] Figure 8 FIG. 8 is a diagram of a video decoder 810 according to another embodiment of the present disclosure. The video decoder 810 is configured to receive an encoded picture as part of an encoded video sequence and decode the encoded picture to generate a reconstructed picture. In an example, the video decoder 810 is used to replace Figure 4 Video decoder 410 in the example.

[0106] 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 are shown coupled together.

[0107] The entropy decoder 871 may be configured to reconstruct certain symbols from the encoded picture, which represent the syntax elements constituting the encoded picture. Such symbols may include, for example, a mode for encoding a block (such as, intra mode, inter mode, bidirectional prediction mode, a merged sub-mode of the latter two, or another sub-mode), prediction information (such as, for example, intra prediction information or inter prediction information) that can be used to identify certain samples or metadata for prediction by the intra decoder 872 or the inter decoder 880, respectively, residual information such as quantized transform coefficients, etc. In the example, when the prediction mode is an 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 can be inversely quantized and provided to the residual decoder 873.

[0108] 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.

[0109] The intra decoder 872 is configured to receive intra prediction information and generate a prediction result based on the intra prediction information.

[0110] 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 (data path not shown, as this may only be low-amount control information).

[0111] The reconstruction module 874 is configured to combine the residual output by the residual decoder 873 with the prediction result (output by the inter-frame prediction module or output by the intra-frame prediction module as appropriate) in the spatial domain to form a reconstructed block, which can be part of a reconstructed picture, which can be part of a reconstructed video. Note that other suitable operations such as deblocking operations can be performed to improve visual quality.

[0112] Note that any suitable technology may be used to implement the video encoders 403, 603, and 703 and the video decoders 410, 510, and 810. In an embodiment, the video encoders 403, 603, and 703 and the video decoders 410, 510, and 810 may be implemented using one or more integrated circuits. In another embodiment, the video encoders 403, 603, and 703 and the video decoders 410, 510, and 810 may be implemented using one or more processors that execute software instructions.

[0113] In the decoding method according to the first embodiment of the present disclosure, a wide angle beyond the range of prediction directions covered by the conventional intra prediction mode is used, which is referred to as a wide-angle intra prediction mode. These wide angles are only applicable to non-square blocks. If the block width is greater than the block height, an angle exceeding 45 degrees in the upper right direction is used (intra prediction mode 34 in HEVC). If the block height is greater than the block width, an angle exceeding 45 degrees in the lower left direction is used (intra prediction mode 2 in HEVC). In the case of applying 35 kinds of HEVC intra prediction modes, mode 2 is referred to as the lower left diagonal mode, and mode 34 is referred to as the upper right diagonal mode.

[0114] As described in U.S. Provisional Application Nos. 62 / 679,664, 62 / 693,050, and 62 / 693,046, for non-square blocks, several normal angle intra prediction modes are replaced with wide angle modes, the entire contents of which are incorporated herein by reference in their entirety. These replaced modes are signaled using the original method and remapped to the index of the wide angle mode after parsing. The total number of intra prediction modes remains unchanged, i.e., 35 as in VVC Test Model (VTM)-1.0, or 67 as in BMS-1.0, and intra mode encoding remains unchanged.

[0115] In case of 35 intra prediction modes, replaced intra prediction modes are shown in Table 1 below.

[0116] condition Replaced intra prediction mode W / H==2 Mode 2, Mode 3, Mode 4 W / H>2 Mode 2, Mode 3, Mode 4, Mode 5, Mode 6 W / H==1 none H / W==1 / 2 Mode 32, Mode 33, Mode 34 H / W<1 / 2 Mode 30, Mode 31, Mode 32, Mode 33, Mode 34

[0117] Table 1

[0118] In case of 67 intra prediction modes, replaced intra prediction modes are shown in Table 2 below.

[0119]

[0120]

[0121] Table 2

[0122] As shown in Table 2, at most 10 patterns are replaced by wide-angle patterns beyond the diagonal direction.

[0123] Fig. 9 An example of how to replace the angle intra mode with the wide angle mode for non-square blocks is shown. In this example, mode 2 and mode 3 are replaced with wide angle modes 35 and 36, respectively, where the direction of mode 35 points in the opposite direction of mode 3, and the direction of mode 36 points in the opposite direction of mode 4.

[0124] Intra-frame sample replacement processing is used in HEVC. The following describes the intra-frame sample replacement processing of the intra-frame mode, which includes a reference sample replacement processing, a filtering processing of a neighboring process, and an intra-frame prediction processing.

[0125] The input to this process is:

[0126] Reference samples p[x][y] for intra sample prediction (where x=-1, y=-1..nTbS*2-1, and x=0..nTbS*2-1, y=-1), transform block size nTbS, and variable cIdx specifying the color component of the current block.

[0127] The output of this process is the modified reference samples p[x][y] (where x=-1, y=-1..nTbS*2-1, and x=0..nTbS*2-1, y=-1) for intra sample prediction.

[0128] Follow the steps below to get the variable bitDepth:

[0129] - If cIdx is equal to 0, bitDepth is set equal to BitDepthY.

[0130] - Otherwise, set bitDepth equal to BitDepthC.

[0131] The values ​​of samples p[x][y] (where x=-1, y=-1..nTbS*2-1, and x=0..nTbS*2-1, y=-1) are modified as follows:

[0132] If all samples p[x][y] (where x=-1, y=-1..nTbS*2-1, and x=0..nTbS*2-1, y=-1) are marked as "not available for intra prediction", the values ​​of all samples p[x][y] are replaced with the value 1<<(bitDepth-1).

[0133] Otherwise (at least one but not all samples p[x][y] are marked as “not available for intra prediction”), the following steps are performed in order:

[0134] 1. When p[-1][nTbS*2-1] is marked as "not available for intra prediction", search from x=-1, y=nTbS*2-1 to x=-1, y=-1, and then search from x=0, y=-1 to x=nTbS*2-1, y=-1. Once a sample p[x][y] marked as "available for intra prediction" is found, the search is terminated and the value of p[x][y] is assigned to p[-1][nTbS*2-1].

[0135] 2. Start from x=-1, y=nTbS*2-2 and search to x=-1, y=-1. When p[x][y] is marked as "not available for intra prediction", replace the value of p[x][y] with the value of p[x][y+1].

[0136] 3. For x=0..nTbS*2-1, y=-1, if p[x][y] is marked as "not available for intra prediction", the value of p[x-1][y] is replaced by the value of p[x][y].

[0137] All samples p[x][y] (where x=-1, y=-1..nTbS*2-1, and x=0..nTbS*2-1, y=-1) are marked as "available for intra prediction".

[0138] Filter adjacent samples. The input of this process is as follows:

[0139] - neighboring samples p[x][y], where x=-1, y=-1..nTbS*2-1, and x=0..nTbS*2-1, y=-1,

[0140] - The variable nTbS specifies the transform block size.

[0141] The output of this process is the filtered samples pF[x][y], where x=-1, y=-1..nTbS*2-1, and x=0..nTbS*2-1, y=-1. The variable filterFlag is derived as follows:

[0142] - Set filterFlag equal to 0 if one or more of the following conditions are true:

[0143] -predModelntra is equal to INTRA_DC.

[0144] -nTbS is equal to 4.

[0145] - Otherwise, the following steps apply:

[0146] - Set the variable minDistVerHor equal to Min(Abs(predModeIntra–26),Abs(predModeIntra–10)).

[0147] -Specify the variable intraHorVerDistThres[nTbS] in Table 3.

[0148] - Follow the steps below to get the variable filterFlag:

[0149] - If minDistVerHor is greater than intraHorVerDistThres[nTbS], set filterFlag equal to 1.

[0150] Otherwise, set filterFlag equal to 0.

[0151] Table 3 below specifies intraHorVerDistThres[nTbS] for various transform block sizes.

[0152] nTbS=8 nTbS=16 nTbS=32 intraHorVerDistThres[nTbS] 7 1 0

[0153] Table 3

[0154] In the case where filterFlag is equal to 1, the following steps apply:

[0155] - Obtain the variable biIntFlag by following the steps below:

[0156] - Set biIntFlag equal to 1 if all of the following conditions are true:

[0157] -strong_intra_smoothing_enabled_flag equal to 1

[0158] -nTbS is equal to 32

[0159] -Abs(p[-1][-1]+p[nTbS*2-1][-1]-2*p[nTbS-1][-1])<(1<<(BitDepthY-5))

[0160] -Abs(p[-1][-1]+p[-1][nTbS*2-1]-2*p[-1][nTbS-1])<(1<<(BitDepthY-5))

[0161] - Otherwise, set biIntFlag equal to 0.

[0162] - Perform filtering as follows:

[0163] If biIntFlag is equal to 1, the filtered sample values ​​pF[x][y] (where x=-1, y=-1..63, and x=0..63, y=-1) are obtained as follows:

[0164] pF[-1][-1]=p[-1][-1]

[0165] For y=0..62(8-31), pF[-1][y]=((63-y)*p[-1][-1]+(y+1)*p[-1]

[63] +32)>>6

[0166] pF[-1]

[63] =p[-1]

[63]

[0167] For x=0..62(8-31), pF[x][-1]=((63-x)*p[-1][-1]+(x+1)*p

[63] [-1]+32)>>6

[0168] pF

[63] [-1]=p

[63] [-1]

[0169] - Otherwise (biIntFlag is equal to 0), the filtered sample value pF[x][y] is obtained according to the following steps (where x=-1, y=-1..nTbS*2-1, and x=0..nTbS*2-1, y=-1):

[0170] pF[-1][-1]=(p[-1][0]+2*p[-1][-1]+p[0][-1]+2)>>2

[0171] For y=0..nTbS*2-2, pF[-1][y]=(p[-1][y+1]+2*p[-1][y]+p[-1][y-1]+2)>>2

[0172] pF[-1][nTbS*2-1]=p[-1][nTbS*2-1]

[0173] For x=0..nTbS*2-2, pF[x][-1]=(p[X-1][-1]+2*p[x][-1]+p[x+1][-1]+2)>>2

[0174] pF[nTbS*2-1][-1]=p[nTbS*2-1][-1]

[0175] Intra prediction modes are specified in the range INTRA_ANGULAR2 to INTRA_ANGULAR34. The inputs to this process are:

[0176] - Intra prediction mode predModeIntra,

[0177] - neighboring samples p[x][y] (where x=-1, y=-1..nTbS*2-1, and x=0..nTbS*2-1, y=-1),

[0178] - a variable nTbS that specifies the transform block size, and

[0179] - Variable cIdx that specifies the color component of the current block.

[0180] The output of this process is the prediction samples predSamples[x][y], where x, y = 0..nTbS-1.

[0181] Fig.10 33 intra angles are shown and Table 4 specifies the mapping between predModeIntra (pMI) and the angle parameter intraPredAngle (iPA).

[0182] pMI 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 iPA - 32 26 21 17 13 9 5 2 0 -2 -5 -9 -13 -17 -21 -26 pMI 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 iPA -32 -26 -21 -17 -13 -9 -5 -2 0 2 5 9 13 17 21 26 32

[0183] Table 4

[0184] like Fig.10 As shown, intraPredAngle is a value indicating a predetermined distance measure relative to the vertical or horizontal mode. The smaller the absolute value of intraPredAngle is, the smaller the distance to the vertical or horizontal mode is.

[0185] Table 5 specifies the relationship between predModeIntra and the inverse angle parameter invAnle.

[0186] predModeIntra 11 12 13 14 15 16 17 18 invAngle -4096 -1638 -910 -630 -482 -390 -315 -256 predModeIntra 19 20 21 22 23 24 25 26 invAngle -315 -390 -482 -630 -910 -1638 -4096 -

[0187] Table 5

[0188] The values ​​of the predicted samples predSamples[x][y] (where x, y = 0..nTbS-1) are obtained by the following steps:

[0189] If predModeIntra is equal to or greater than 18, the following ordered steps apply:

[0190] 1. Specify the reference sample array ref[x] as follows:

[0191] ref[x]=p[-1+x][-1], where x=0..nTbS.

[0192] If intraPredAngle is less than 0, the primary reference sample array is extended as follows:

[0193] When (nTbS*intraPredAngle)>>5 is less than -1, ref[x]=p[-1][-1+((x*invAngle+128)>>8)], where x=-1..(nTbS*intraPredAngle)>>5.

[0194] Otherwise, ref[x]=p[-1+x][-1], where x=nTbS+1..2*nTbS.

[0195] 2. Obtain the value of the predicted sample predSamples[x][y] (where x, y = 0..nTbS-1) according to the following steps:

[0196] a. Obtain the index variable iIdx and the multiplication factor iFact by following the steps below:

[0197] iIdx=((y+1)*intraPredAngle)>>5

[0198] iFact=((y+1)*intraPredAngle)&31

[0199] b. Depending on the value of iFact, apply the following steps:

[0200] If iFact is not equal to 0, the value of the predicted sample predSamples[x][y] is obtained by the following steps:

[0201] predSamples[x][y]=((32-iFact)*ref[x+iIdx+1]+iFact*ref[x+iIdx+2]+16)>>5

[0202] Otherwise, follow the steps below to get the value of the predicted sample predSamples[x][y]:

[0203] predSamples[x][y]=ref[x+iIdx+1]

[0204] c. When predModeIntra is equal to 26 (vertical), cIdx is equal to 0 and nTbS is less than 32, the following filtering applies for x=0, y=0..nTbS-1:

[0205] predSamples[x][y]=Clip1Y(p[x][-1]+((p[-1][y]-p[-1]

[0206] [-1])>>1)),

[0207] Otherwise (predModeIntra is less than 18), the following ordered steps apply:

[0208] 1. Specify the reference sample array ref[x] as follows:

[0209] - The following steps apply:

[0210] ref[x]=p[-1][-1+x], where x=0..nTbS

[0211] - If intraPredAngle is less than 0, extend the primary reference sample array as follows:

[0212] - In the case where (nTbS*IntraPredAngle)>>5 is less than -1,

[0213] ref[x]=p[-1+((x*invAngle+128)>>8)][-1],

[0214] where x = -1..(nTbS*intraPredAngle)>>5

[0215] -otherwise,

[0216] ref[x]=p[-1][-1+x], where x=nTbS+1..2*nTbS

[0217] 2. Obtain the value of the predicted sample predSamples[x][y] (where x, y = 0..nTbS-1) according to the following steps:

[0218] a. Obtain the index variable iIdx and the multiplication factor iFact by following the steps below:

[0219] iIdx=((x+l)*intraPredAngle)>>5

[0220] iFact=((x+1)*intraPredAngle)&31

[0221] b. Depending on the value of iFact, apply the following steps:

[0222] -If iFact is not equal to 0, the value of the predicted sample predSamples[x][y] is obtained according to the following steps:

[0223] predSamples[x][y]=((32-iFact)*ref[y+iIdx+1]+

[0224] iFact*ref[y+iIdx+2]+16)>>5

[0225] Otherwise, the value of the predicted sample predSamples[x][y] is obtained by the following steps:

[0226] predSamples[x][y]=ref[y+iIdx+1]

[0227] c. When predModeIntra is equal to 10 (horizontal), cIdx is equal to 0 and nTbS is less than 32, the following filtering applies for x=0..nTbS-1, y=0:

[0228] predSamples[x][y]=Clip1Y(p[-1][y]+((p[x][-1]-p[-1][-1])>>1)).

[0229] exist Fig.11A and Fig. 11B In the first embodiment of the decoding method according to the present disclosure shown, the wide angle mode is included when specifying the relationship between predModeIntra and IntraPredAngle. Up to ten additional wide angle modes are added beyond the diagonal direction. This relationship is specified as set forth in Table 6, which can be implemented as a lookup table.

[0230] pMI -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 iPA 114 93 79 68 60 54 49 45 39 35 - - 32 29 26 23 21 pMI 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 iPA 19 17 15 13 11 <![CDATA[ 9 ]]> 7 5 3 2 1 0 -1 -2 -3 -5 -7 pMI 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 iPA -9 -11 -13 -25 -17 -19 -21 -23 -26 -29 -32 -29 -26 -23 -21 -19 -17 pMI 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 iPA -15 -13 -11 -9 -7 -5 -3 -2 -1 0 1 2 3 5 7 9 11 pMI 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 iPA 13 15 17 19 21 23 26 29 32 35 39 45 49 54 60 68 79 pMI 75 76 iPA 93 114

[0231] Table 6

[0232] The ten intra modes below 0 are represented as -1 to -10, and the ten modes above 66 are represented as 67 to 76. The value of the added angle varies from 35 to 114.

[0233] In step 1100, one or more syntax elements are decoded from a video sequence. Figure 8 In the example of , entropy decoder 871 decodes specific symbols representing syntax elements constituting the encoded picture from the encoded video sequence. Intra-frame decoder 872 generates a prediction result. Such symbols may include, for example, prediction information, and the intra-frame prediction mode may be determined. According to the relationship shown in Table 6, the intra-frame prediction angle is determined from the intra-frame prediction mode (step 1101). The samples of the block are reconstructed using the determined intra-frame prediction angle (step 1102). For example, the samples of the block are reconstructed by reconstruction module 874.

[0234] The relationship between the intra prediction angle and the intra prediction mode may be stored in a lookup table (step 1110), such as in the reconstruction module 874. The intra prediction angle may be determined from the lookup table using the determined intra prediction mode (step 1111).

[0235] The method can be applied to reconstruct at least one sample in a non-square block and a square block using the relationship between the intra prediction mode and the intra prediction angle. The non-square block uses a wide angle mode.

[0236] In another embodiment of the method according to the present disclosure, the values ​​of predModeIntra and intraPredAngle are modified. In these other embodiments, the block height is given as TbW and the block width is given as TbH. In a second embodiment, the values ​​of predModeIntra and wideAngle are modified as follows:

[0237] - If nTbW>nTbH and intraPredAngle>((32*nTbH / nTbW)+1) and predModeIntra<34

[0238] - If intraPredAngle>9, then predModeIntra=predModeIntra+65, and perform intra-frame smoothing;

[0239] - Otherwise, predModeIntra=66,

[0240] - If nTbH>nTbW and intraPredAngle>((32*nTbW / nTbH)+1) and predModeIntra>34

[0241] - If intraPredAngle>9, then predModeIntra=predModeIntra-67, and intra-frame smoothing is performed;

[0242] -Otherwise, predModeIntra=2.

[0243] In the third implementation, the values ​​of predModeIntra and wideAngle are modified as follows:

[0244] - If nTbW>nTbH and intraPredAngle>((32*nTbH / nTbW)+1) and predModeIntra<34

[0245] - If intraPredAngle>9, then predModeIntra=predModeIntra+65, and perform intra-frame smoothing;

[0246] - Otherwise, predModeIntra=68-predModeIntra,

[0247] - If nTbH>nTbW and intraPredAngle>((32*nTbW / nTbH)+1) and predModeIntra>34

[0248] - If intraPredAngle>9, then predModeIntra=predModeIntra-67, and intra-frame smoothing is performed;

[0249] -Otherwise, predModeIntra=68-predModeIntra.

[0250] In the fourth implementation, the values ​​of predModeIntra and wideAngle are modified as follows:

[0251] - If nTbW>nTbH and intraPredAngle>((32*nTbH / nTbW)+1) and predModeIntra<34

[0252] - If intraPredAngle>9, then predModeIntra=predModeIntra+65, and perform intra-frame smoothing;

[0253] - Otherwise, predModeIntra=76,

[0254] - If nTbH>nTbW and intraPredAngle>((32*nTbW / nTbH)+1) and predModeIntra>34

[0255] - If intraPredAngle>9, then predModeIntra=predModeIntra-67, and intra-frame smoothing is performed;

[0256] -Otherwise, predModeIntra=-10.

[0257] In the fifth implementation, the values ​​of predModeIntra and wideAngle are modified as follows:

[0258] - if nTbW>nTbH and intraPredAngle>((32*nTbH / nTbW)+1) and predModeIntra<34 and intra smoothing is performed;

[0259] - if intraPredAngle>9, then predModeIntra=predModeIntra+65;

[0260] - Otherwise, predModeIntra=68-predModeIntra,

[0261] - if nTbH>nTbW and intraPredAngle>((32*nTbW / nTbH)+1) and predModeIntra>34 and intra smoothing is performed;

[0262] - if intraPredAngle>9, then predModeIntra=predModeIntra-67;

[0263] -Otherwise, predModeIntra=68-predModeIntra.

[0264] Other embodiments of the present disclosure are described below. The described methods can be used alone or in combination in any order. In addition, the embodiments can be implemented by processing circuits (e.g., one or more processors or one or more integrated circuits). In one example, one or more processors execute a program stored in a non-transient computer readable medium.

[0265] In the following, if the block width is equal to or greater than the block height, the top row is referred to as the long side and the left column is referred to as the short side. Otherwise, the top row is referred to as the short side and the left column is referred to as the long side. The block width is represented by nWidth (or nTbW), and the block height is represented by nHeight (or nTbH).

[0266] When filling an array / buffer with N reference samples, this means that the reference sample values ​​are filled by neighboring reconstructed samples located at the associated positions of the reference samples, or are copied from already filled reference samples, or are derived from reference samples that have been filled using a predefined function (e.g. linear extrapolation).

[0267] Given a set of all available intra prediction directions, there is a constraint for a specific block size WxH: only a predefined range (or group, or number) of reference samples can be used for intra prediction, and any intra prediction direction S using reference samples outside the predefined range (or group, or number) of reference samples is mapped to a different intra prediction direction X. The following are several implementations.

[0268] In one embodiment, the mapped intra prediction direction X is included in the set of all available intra prediction directions.

[0269] In another embodiment, the mapped intra prediction direction X does not use reference samples outside the above predefined range (or group, or number) of reference samples.

[0270] In yet another embodiment, the predefined range (or group, or number) of reference samples includes 2*W+N top-adjacent reference samples and 2*H+M left-adjacent reference samples. Example values of M and N include 1, 2, 3, 4, ..., 128.

[0271] In another embodiment, X is the intra prediction direction within the diagonal frame. For example, when applying 33 angular intra prediction modes, S is mapped to 2 or 34 (as specified in Table 5 above). For another example, when applying 65 angular intra prediction modes, S is mapped to 2 or 66. For another example, when W > H, X is mapped to mode 34 (when applying 33 angular intra prediction modes) or 66 (when applying 65 angular intra prediction modes). For another example, when W < H, X is mapped to mode 2.

[0272] In yet another embodiment, S = K - X, where K is a predefined constant value. Example values are 36 (when applying 33 angular intra prediction modes) and 68 (when applying 65 angular intra prediction modes).

[0273] In an additional embodiment, X is the widest intra prediction angle (with the largest index or the smallest index) within the set of all available intra prediction directions.

[0274] In another embodiment, X is a predefined intra prediction mode. Example predefined intra prediction modes include: horizontal prediction mode, vertical prediction mode, planar prediction mode, and DC prediction mode.

[0275] In another embodiment, S is mapped to one of the intra prediction directions X in the set of all available intra prediction directions, but intra smoothing is applied differently. For example, if intra smoothing is not applied to the intra prediction direction X, then intra smoothing is applied after S is mapped to the intra prediction direction X. For another example, if intra smoothing has been applied to the intra prediction direction X, then intra smoothing is not applied after S is mapped to the intra prediction direction X.

[0276] For a rectangular block, whether to apply intra smoothing depends on the block width and / or the block height, rather than the block area size. Several embodiments using this concept are described below.

[0277] In one embodiment, when using the Planar mode, whether to apply intra smoothing to the top-adjacent reference samples depends on the block width, and whether to apply intra smoothing to the left-adjacent reference samples depends on the block height.

[0278] In another embodiment, when the angle mode is used, whether intra-frame smoothing is applied to the top adjacent reference sample depends on the block width, and whether intra-frame smoothing is applied to the left adjacent reference sample depends on the block height. In the example, two tables (as shown below) are used to decide whether intra-frame smoothing is applied. Table 7 below is used to decide whether intra-frame smoothing is applied to the left reference sample given the block height and intra-frame mode ipred. When Abs(ipred-HOR_IDX) is greater than intraVerDistThres[nTbH], intra-frame smoothing is applied to the left reference sample, otherwise, intra-frame smoothing is not applied. HOR_IDX indicates the intra-frame mode index of horizontal intra-frame prediction. When 33 angle modes are applied, the index is 10, and when 65 angle modes are applied, the index is 18. When 65 angle modes are applied, the thresholds in the following table are applied.

[0279] nTbH=4 nTbH=8 nTbH=16 nTbH=32 nTbH=64 intraVerDistThrcs[nTbH] 20 14 2 0 20

[0280] Table 7

[0281] Table 8 below is used to decide whether to apply intra smoothing to the top reference sample given the block height and intra mode ipred. When Abs(ipred-VER_IDX) is greater than intraVerDistThres[nTbW], intra smoothing is applied to the top reference sample, otherwise, intra smoothing is not applied. VER_IDX indicates the intra mode index of horizontal intra prediction, which is 26 when the 33 angle mode is applied and 50 when the 65 angle mode is applied. When the 65 angle mode is applied, the threshold in the following table is applied.

[0282] nTbW=4 nTbW=8 nTbW=16 nTbW=32 nTbW=64 intraHorDistThrcs[nTbW] 16 14 2 0 16

[0283] Table 8

[0284] In another aspect of the embodiment, intra-frame smoothing is applied for a specific mode, color component or coding tool.Several embodiments are described below.

[0285] In one embodiment, intra-frame smoothing is never applied to planar mode.

[0286] In another embodiment, intra-frame smoothing is always applied to planar mode.

[0287] In another embodiment, intra-frame smoothing is always applied to DC mode.

[0288] In another embodiment, for wide-angle intra prediction, intra smoothing is applied to both luma and chroma components.

[0289] In another embodiment, intra-frame smoothing is applied when transform types other than DCT-2 are used.

[0290] In another embodiment, intra-frame smoothing is never applied when transform types other than DCT-2 are used.

[0291] In another embodiment, when using PDPC (Position-Dependent Prediction Combination), intra-frame smoothing is always applied.

[0292] In another embodiment, intra-frame smoothing is never applied when PDPC is used.

[0293] In another embodiment, when using NSST (Non-Separable Secondary Transform), intra-frame smoothing is always applied.

[0294] In another embodiment, intra-frame smoothing is never applied when using NSST.

[0295] In one embodiment, intra-frame smoothing is never applied to CCLM (Cross-Component Linear Mode) mode.

[0296] In another embodiment, intra-frame smoothing is always applied for CCLM mode.

[0297] PDPC can be applied to angular patterns that approximate the diagonal direction of its block shape, where the diagonal direction is indicated by a line connecting the upper right corner and the lower left corner. Fig.12 As shown, the prediction angle (solid arrow) located in the textured triangle area (120) on the upper left is an intra-frame prediction angle in the diagonal direction, and the prediction angles (dashed angles) 121 and 122 located outside the textured triangle area on the upper left are intra-frame prediction angles beyond the diagonal direction. Another embodiment is described below.

[0298] In one embodiment, the number of modes for applying PDPC is the same for different block shapes.

[0299] In another embodiment, the number of modes for applying PDPC is different for square blocks and non-square blocks.

[0300] In another embodiment, when the current block is a non-square block, the number of modes for applying PDPC is different for the lower left and upper right diagonal directions.

[0301] In another embodiment, when the width is greater than the height, PDPC is not applied to the lower left angle below the horizontal direction, ie, Mode 2 to Mode 17.

[0302] In another embodiment, when the height is greater than the width, PDPC is not applied to the upper right angle above the vertical direction, ie, mode 51 to mode 66.

[0303] The above techniques and implementations can be implemented as computer software using computer-readable instructions and physically stored in one or more computer-readable media. For example, Fig.13 A computer system 1300 suitable for implementing certain embodiments of the disclosed subject matter is shown.

[0304] Computer software may be encoded using any suitable machine code or computer language, to which mechanisms such as assembly, compilation, linking, etc. may be applied 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 interpretation, microcode execution, etc.

[0305] 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. In this application, the term "plurality" refers to two or more.

[0306] Fig.13 The components for computer system 1300 shown in the example are exemplary in nature and are not intended to suggest any limitation on the scope of use or functionality of computer software implementing embodiments of the present disclosure. Nor should the configuration of components be interpreted as having any dependency or requirement related to any one or combination of components shown in the exemplary embodiment of computer system 1300.

[0307] Computer system 1300 may include certain human-machine interface input devices. Such human-machine interface input devices may be responsive to inputs implemented by one or more human users through, for example, tactile inputs (such as keystrokes, swipes, data glove movements), audio inputs (such as voice, tapping), visual inputs (such as gestures), olfactory inputs (not shown). Human-machine interface devices may also be used to capture certain media that are not necessarily directly related to a person's conscious input, for example, audio (such as voice, music, ambient sound), images (such as scanned images, photographic images obtained from a still image camera), videos (such as two-dimensional video, three-dimensional video including stereoscopic video).

[0308] The input human-machine interface device may include one or more of the following (only one of each is depicted): keyboard 1301, mouse 1302, touch pad 1303, touch screen 1310, data gloves (not shown), joystick 1305, microphone 1306, scanner 1307, camera 1308.

[0309] The computer system 1300 may also include certain human-machine interface output devices. Such human-machine interface output devices may stimulate one or more senses of a human user through, for example, tactile output, sound, light, and smell / taste. Such human-machine interface output devices may include tactile output devices (e.g., tactile feedback through a touch screen 1310, a data glove (not shown), or a joystick 1305, but there may also be tactile feedback devices that do not serve as input devices), audio output devices (such as: speakers 1309, headphones (not depicted)), visual output devices (such as screens 1310, including CRT screens, LCD screens, plasma screens, OLED screens, each with or without touch screen input capabilities, each with or without tactile feedback capabilities - some of these screens may be able to output two-dimensional visual outputs or more than three-dimensional outputs through means such as stereoscopic image output; virtual reality glasses (not depicted), holographic displays, and smoke boxes (not depicted)) and printers (not depicted).

[0310] The computer system 1300 may also include human-accessible storage devices and their associated media, such as optical media including CD / DVD ROM / RW 1320 with CD / DVD etc. media 1321, thumb drive 1322, removable hard drive or solid state drive 1323, traditional magnetic media such as tapes and floppy disks (not depicted), dedicated ROM / ASIC / PLD based devices such as security dongles (not depicted), etc.

[0311] 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 include transmission media, carrier waves, or other transient signals.

[0312] The computer system 1300 may also include an interface to one or more communication networks. The network may be, for example, wireless, wired, optical. The network may also be local, wide area, urban, vehicle-mounted and industrial, real-time, delay-tolerant, etc. Examples of networks include local area networks such as Ethernet, wireless LAN, 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-mounted and industrial (including CANBus), etc. Some networks typically require an external network interface adapter attached to some universal data ports or peripheral buses 1349 (such as, for example, the USB port of the computer system 1300); other interfaces are typically integrated into the core of the computer system 1300 by attaching to the system bus described below (for example, an Ethernet interface integrated into a PC computer system or a cellular network interface integrated into a smart phone computer system). Using any of these networks, the computer system 1300 can communicate with other entities. Such communications may be one-way, receive-only (e.g., broadcast television), one-way send-only (e.g., CANBus to certain CANBus devices), or two-way, for example, to other computer systems using a local area digital network or a wide area digital network. Certain protocols and protocol stacks may be used on each of these networks and network interfaces as described above.

[0313] The above-mentioned human-machine interface device, human-accessible storage device, and network interface may be attached to the core 1340 of the computer system 1300 .

[0314] The core 1340 may include one or more central processing units (CPUs) 1341, graphics processing units (GPUs) 1342, dedicated programmable processing units in the form of field programmable gate arrays (FPGAs) 1343, hardware accelerators 1344 for certain tasks, and the like. These devices, along with read-only memory (ROM) 1345, random access memory 1346, internal mass storage devices such as internal non-user accessible hard drives, SSDs, and the like 1347, may be connected via a system bus 1348. In some computer systems, the system bus 1348 may be accessed in the form of one or more physical plugs to enable expansion by additional CPUs, GPUs, and the like. Peripheral devices may be attached to the system bus 1348 of the core directly or via a peripheral bus 1349. The architecture of the peripheral bus includes PCI, USB, and the like.

[0315] The CPU 1341, GPU 1342, FPGA 1343, and accelerator 1344 may execute certain instructions, which in combination may constitute the above-mentioned computer code. The computer code may be stored in ROM 1345 or RAM 1346. Transitional data may also be stored in RAM 1346, while permanent data may be stored in, for example, an internal mass storage device 1347. Fast storage and retrieval for any of the storage devices may be achieved by using a cache memory, which may be closely associated with one or more CPUs 1341, GPUs 1342, mass storage devices 1347, ROM 1345, RAM 1346, etc.

[0316] The computer readable medium may have computer codes for performing various computer-implemented operations. The media and computer codes may be those specially designed and constructed for the purposes of the present disclosure, or they may be of a type well known and available to those skilled in the art of computer software.

[0317] As an example and not limitation, a computer system 1300 having an architecture, and in particular a core 1340, can provide functionality due to a processor (including a CPU, GPU, FPGA, accelerator, etc.) executing software embodied in one or more tangible computer-readable media. Such a computer-readable medium can be a medium associated with a user-accessible mass storage device as described above, and certain storage devices of the core 1340 having a non-transient nature, such as a core mass storage device 1347 or a ROM 1345. Software implementing various embodiments of the present disclosure can be stored in such a device and executed by the core 1340. Depending on specific needs, the computer-readable medium may include one or more memory devices or chips. The software can enable the core 1340, and in particular the processor therein (including a CPU, GPU, FPGA, etc.), to perform a specific process or a specific part of a specific process described herein, including defining a data structure stored in the RAM 1346 and modifying these data structures according to the process defined by the software. Additionally or alternatively, a computer system may provide functionality due to logic hardwired or otherwise embodied in circuitry (e.g., accelerator 1344) that may operate in place of or in conjunction with software to perform a particular process or a particular portion of a particular process described herein. Where appropriate, references to software may include logic, and vice versa. Where appropriate, references to computer-readable media may include circuits storing software for execution (e.g., integrated circuits (ICs)), circuits embodying logic for execution, or both. The present disclosure includes any suitable combination of hardware and software.

[0318] Appendix A: Acronyms

[0319] JEM: joint exploration model

[0320] VVC: versatile video coding

[0321] BMS: benchmark set

[0322] MV: Motion Vector

[0323] HEVC: High Efficiency Video Coding

[0324] SEI: Supplementary Enhancement Information, supplementary enhancement information

[0325] VUI: Video Usability Information, video availability information

[0326] GOP: Groups of Pictures, picture group

[0327] TU: Transform Unit

[0328] PU: Prediction Unit

[0329] CTU: Coding Tree Unit, coding tree unit

[0330] CTB: CodingTree Block, coding tree block

[0331] PB: Prediction Block

[0332] HRD: Hypothetical Reference Decoder, Hypothetical Reference Decoder

[0333] SNR: Signal Noise Ratio

[0334] CPU: Central Processing Unit, central processing unit

[0335] GPU: Graphics Processing Unit, Graphics Processing Unit

[0336] CRT: Cathode Ray Tube

[0337] LCD: Liquid-Crystal Display

[0338] OLED: Organic Light-Emitting Diode

[0339] CD: Compact Disc

[0340] DVD: Digital Video Disc

[0341] ROM:Read-Only Memory

[0342] RAM: Random Access Memory

[0343] ASIC: Application-Specific Integrated Circuit

[0344] PLD:Programmable Logic Device

[0345] LAN: Local Area Network

[0346] GSM: Global System for Mobile communications

[0347] LTE: Long-Term Evolution

[0348] CANBus: Controller Area Network Bus

[0349] USB: Universal Serial Bus

[0350] PCI: Peripheral Component Interconnect, peripheral component interconnect

[0351] FPGA: Field Programmable Gate Areas, field programmable gate array

[0352] SSD: solid-state drive

[0353] IC:Integrated Circuit

[0354] CU: Coding Unit

[0355] Although the present disclosure has described several exemplary embodiments, there are changes, permutations, and various replacement equivalents that fall within the scope of the present disclosure. It will therefore be appreciated that, although not explicitly shown or described herein, those skilled in the art will be able to conceive of many systems and methods that embody the principles of the present disclosure and are therefore within its spirit and scope.

Claims

1. A method for video encoding, characterized in that The method comprises: determining an intra prediction mode for encoding a current block, the current block being a non-square block; Determining an intra-frame prediction angle corresponding to the intra-frame prediction mode based on a predetermined corresponding relationship, wherein the predetermined corresponding relationship is a corresponding relationship between a plurality of intra-frame prediction angles and a plurality of intra-frame prediction modes; and generating prediction information indicating the determined intra prediction mode, Wherein, the current block has a width W and a height H; Among the 67 intra prediction modes, when W / H==1 / 2, the determined intra prediction mode includes a first wide-angle prediction mode, which is obtained based on the replacement of the normal angle intra prediction modes 61, 62, 63, 64, 65 and 66; When W / H==2, the determined intra prediction mode includes a second wide-angle prediction mode, which is obtained based on the normal angle intra prediction modes 2, 3, 4, 5, 6 and 7 being replaced; The first wide-angle prediction mode exceeds a diagonal mode in a lower left direction of the current block, and the second wide-angle prediction mode exceeds a diagonal mode in an upper right direction of the current block.

2. The method according to claim 1, characterized in that The lower left diagonal mode is at an angle of 45 degrees to the horizontal direction at the lower left, and the upper right diagonal mode is at an angle of 45 degrees to the horizontal direction at the lower right.

3. The method according to claim 2, characterized in that The intra prediction angle corresponds to intraPredAngle, the intra prediction mode corresponds to predModeIntra, and The relationship is determined according to the following table: 。 4. The method according to any one of claims 1 to 3, characterized in that: The first wide-angle prediction modes each have an integer value in the range of -1 to -10; and The second wide-angle prediction modes have integer values ​​ranging from 67 to 76, respectively.

5. The method according to claim 4, characterized in that: In the relationship, an intra prediction angle corresponding to each of the first wide-angle prediction mode and the second wide-angle prediction mode is within a range of 35 to 114.

6. The method according to any one of claims 1 to 3, characterized in that: The value of the first wide-angle prediction mode is less than mode 2 of the High Efficiency Video Coding (HEVC) standard; and The value of the second wide-angle prediction mode exceeds mode 34 of the HEVC standard.

7. The method according to any one of claims 1 to 3, characterized in that: include: When the width W is greater than the height H, and The intra prediction angle is greater than ((32*H / W)+1), and When the intra prediction mode is less than 34, When the intra prediction angle is greater than 9, the value of the intra prediction mode is increased by 65, otherwise, the intra prediction mode is set to 66.

8. The method according to any one of claims 1 to 3, characterized in that: include: When the width W is smaller than the height H, and The intra prediction angle is greater than ((32*W / H)+1), and When the intra prediction mode is greater than 34, When the intra prediction angle is greater than 9, the value of the intra prediction mode is subtracted by 67, otherwise, the intra prediction mode is set to 2.

9. The method according to any one of claims 1 to 3, characterized in that: include: When the width W is greater than the height H, and The intra prediction angle is greater than ((32*H / W)+1), and When the intra prediction mode is less than 34, When the intra prediction angle is greater than 9, the value of the intra prediction mode is increased by 65, otherwise, the intra prediction mode is set to 68 minus the value of the intra prediction mode.

10. The method according to any one of claims 1 to 3, characterized in that: include: When the width W is smaller than the height H, and The intra prediction angle is greater than ((32*W / H)+1), and When the intra prediction mode is greater than 34, When the intra prediction angle is greater than 9, the value of the intra prediction mode is subtracted by 67, otherwise, the intra prediction mode is set to 68 minus the value of the intra prediction mode.

11. The method according to any one of claims 1 to 3, characterized in that: include: When the width W is greater than the height H, and The intra prediction angle is greater than ((32*H / W)+1), and When the intra prediction mode is less than 34, When the intra prediction angle is greater than 9, the value of the intra prediction mode is increased by 65, otherwise, the intra prediction mode is set to 76.

12. The method according to any one of claims 1 to 3, characterized in that: include: When the width W is smaller than the height H, and The intra prediction angle is greater than ((32*W / H)+1), and When the intra prediction mode is greater than 34, When the intra prediction angle is greater than 9, the value of the intra prediction mode is subtracted by 67, otherwise, the intra prediction mode is set to -10.

13. The method according to any one of claims 1 to 3, characterized in that: Among the 67 intra prediction modes, when W / H<1 / 2, the first wide-angle prediction mode is obtained by replacing the normal angle intra prediction modes 57, 58, 59, 60, 61, 62, 63, 64, 65 and 66; When W / H>2, the second wide-angle prediction mode is obtained by replacing the normal-angle intra prediction modes 2, 3, 4, 5, 6, 7, 8, 9, 10 and 11.

14. A device for video encoding, characterized in that The device comprises: A determination module configured to determine an intra prediction mode for encoding a current block, the current block being a non-square block; a corresponding module configured to determine an intra-frame prediction angle corresponding to the intra-frame prediction mode based on a predetermined corresponding relationship, wherein the predetermined corresponding relationship is a corresponding relationship between a plurality of intra-frame prediction angles and a plurality of intra-frame prediction modes; and a generating module configured to generate prediction information indicating the determined intra prediction mode, Wherein, the current block has a width W and a height H; Among the 67 intra prediction modes, when W / H==1 / 2, the determined intra prediction mode includes a first wide-angle prediction mode, which is obtained based on the replacement of the normal angle intra prediction modes 61, 62, 63, 64, 65 and 66; When W / H==2, the determined intra prediction mode includes a second wide-angle prediction mode, which is obtained based on the normal angle intra prediction modes 2, 3, 4, 5, 6 and 7 being replaced; The first wide-angle prediction mode exceeds a diagonal mode in a lower left direction of the current block, and the second wide-angle prediction mode exceeds a diagonal mode in an upper right direction of the current block.

15. A video encoder for video encoding, comprising: A processing circuit configured to perform the method as claimed in any one of claims 1 to 13.

16. A non-transitory computer-readable medium storing instructions, which, when executed by a computer for video encoding, cause the computer to perform the method of any one of claims 1 to 13.

17. A computer device, characterized in that: The device comprises a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is configured to execute the method according to any one of claims 1 to 13 according to the instructions in the program code.

18. A method for processing a video bitstream, characterized in that: The video bitstream is generated according to the method according to any one of claims 1 to 13.

Images