HK40079470B - Video encoding and decoding method and related apparatus - Google Patents

Description

A video encoding/decoding method and related apparatus

Cross-references to related applications

This application claims priority to U.S. Provisional Application No. 62/731,776, filed September 14, 2018, and U.S. Application No. 16/234,993, filed December 28, 2018, the disclosures of which are incorporated herein by reference in their entirety.

Technical Field

This disclosure relates to video processing technology, and more particularly to a video encoding/decoding method and related apparatus.

Background Technology

Figure 5 illustrates the intra-prediction modes used in High Efficiency Video Coding (HEVC). In HEVC, there are a total of 35 intra-prediction modes, where mode 10 is a horizontal mode (501), mode 26 is a vertical mode (502), and modes 2, 18, and 34 are diagonal modes (503). The intra-prediction modes are represented by signals using three most probable modes (MPMs) and the remaining 32 modes.

To encode intra-frame modes, a Most Probable Modes (MPMs) list of size 3 is constructed based on the intra-frame modes of neighboring blocks. This MPM list is referred to as the MPM list or the master MPM list. If an intra-frame mode does not come from the MPM list, a signal flag is used to indicate whether the intra-frame mode belongs to the selected mode.

The following illustrates the process for generating the MPM list. Here, `leftIntraDir` indicates the mode in the left block, and `aboveIntraDir` indicates the mode in the upper block. If either the left or upper block is currently unavailable, `leftIntraDir` or `aboveIntraDir` is set to the index `DC_IDX`. Furthermore, the variables "offset" and "mod" are constant values, set to 29 and 32 respectively.

●If(leftIntraDir＝＝aboveIntraDir&&leftIntraDir>DC_IDX)

○MPM[0]＝leftIntraDir;

○MPM[1]=((leftIntraDir+offset)%mod)+2;

○MPM[2]=((leftIntraDir-1)%mod)+2;

●Else if(leftIntraDir＝＝aboveIntraDir)

○MPM[0]＝PLANAR_IDX;

○MPM[1]＝DC_IDX;

○MPM[2]＝VER_IDX;

●Else if(leftIntraDir!=aboveIntraDir)

○MPM[0]＝leftIntraDir;

○MPM[1]＝aboveIntraDir;

○If(leftIntraDir>0&&aboveIntraDir>0)

■MPM[2]＝PLANAR_IDX；

○Else

■MPM[2]=(leftIntraDir+aboveIntraDir)<2? VER_IDX:DC_IDX;

Given that only two adjacent patterns can be accessed, how to generate an MPM list that includes more angle patterns for non-zero rows is a technical problem that needs to be solved.

Summary of the Invention

According to at least one embodiment, a video decoding method, executed by at least one processor, is used to control multi-line intra-frame prediction using non-zero reference lines. The method includes: determining whether the intra-frame prediction mode of a first neighboring block of the current block is an angle mode. The method may further include: determining whether the intra-frame prediction mode of a second neighboring block of the current block is an angle mode. The method may further include: generating an MPM list including six candidate modes for intra-frame prediction of the current block, wherein all six candidate modes are angle modes. The MPM list can be generated such that it includes the intra-frame prediction mode of the first neighboring block if the intra-frame prediction mode of the first neighboring block is determined to be an angle mode, and includes the intra-frame prediction mode of the second neighboring block if the intra-frame prediction mode of the second neighboring block is determined to be an angle mode.

According to at least one embodiment, an apparatus for controlling multi-line intra-frame prediction using non-zero reference lines to decode a video sequence can be provided. The apparatus may include: at least one memory configured to store computer program code; and at least one processor configured to access the at least one memory and operate according to the computer program code. The computer program code may include first determining code configured to cause the at least one processor to determine whether the intra-frame prediction mode of a first adjacent block of the current block is an angle mode. The computer program code may further include second determining code configured to cause the at least one processor to determine whether the intra-frame prediction mode of a second adjacent block of the current block is an angle mode. The computer program code may further include generating code configured to cause the at least one processor to generate an MPM list including six candidate modes for intra-frame prediction of the current block, wherein all six candidate modes are angle modes. The generation code can also be configured to cause at least one of the processors to generate an MPM list, such that the MPM list includes the intra prediction mode of the first adjacent block when the intra prediction mode of the first adjacent block is determined to be an angle mode, and includes the intra prediction mode of the second adjacent block when the intra prediction mode of the second adjacent block is determined to be an angle mode.

According to at least one embodiment, a non-transitory computer-readable storage medium storing instructions that can cause at least one processor to determine whether the intra-prediction mode of a first neighboring block of a current block is an angle mode. The instructions can also cause the at least one processor to determine whether the intra-prediction mode of a second neighboring block of the current block is an angle mode. The instructions can further cause the at least one processor to generate an MPM list including six candidate modes for intra-prediction of the current block, wherein all six candidate modes are angle modes. The instructions can cause at least one processor to generate an MPM list such that the MPM list includes the intra-prediction mode of the first neighboring block if the intra-prediction mode of the first neighboring block is determined to be an angle mode, and includes the intra-prediction mode of the second neighboring block if the intra-prediction mode of the second neighboring block is determined to be an angle mode.

Therefore, when using non-zero reference rows to control multi-row intra-prediction, the process involves determining whether the intra-prediction mode of the first adjacent block of the current block is an angle mode; determining whether the intra-prediction mode of the second adjacent block of the current block is an angle mode; and generating a most probable mode (MPM) list. The MPM list includes multiple candidate modes for intra-prediction of the current block, all of which are angle modes. Furthermore, if the intra-prediction mode of the first adjacent block is determined to be an angle mode, the MPM list includes the intra-prediction mode of the first adjacent block; and if the intra-prediction mode of the second adjacent block is determined to be an angle mode, the MPM list includes the intra-prediction mode of the second adjacent block. This achieves the generation of an MPM list containing more angle modes for non-zero rows.

Attached Figure Description

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

Figure 1 is a simplified block diagram of a communication system according to an embodiment;

Figure 2 is a simplified block diagram of a streaming system according to an embodiment;

Figure 3 is a simplified block diagram of the video decoder and display according to an embodiment;

Figure 4 is a simplified block diagram of the video encoder and video source according to the embodiment;

Figure 5 is a diagram of intra-frame prediction modes in HEVC;

Figure 6 is a diagram of the intra-prediction mode in Multifunctional Video Coding Draft 2;

Figure 7 is a diagram illustrating an example of a reference row used for multi-line intra-frame prediction;

Figure 8 is a diagram showing an example of the top and left blocks relative to the current block;

Figure 9 is a diagram of a computer system suitable for implementing the implementation method.

Detailed Implementation

Figure 1 shows a simplified block diagram of a communication system (100) according to an embodiment of the present disclosure. The system (100) may include at least two terminals (110 to 120) interconnected via a network (150). For unidirectional data transmission, the first terminal (110) may encode video data at a local location for transmission to the other terminal (120) via the network (150). The second terminal (120) may receive the encoded video data from the other terminal from the network (150), decode the encoded data, and display the recovered video data. Unidirectional data transmission may be common in media service applications, etc.

Figure 1 illustrates a second pair of terminals (130, 140) provided to support bidirectional transmission of encoded video, for example, during video conferencing. For bidirectional data transmission, each terminal (130, 140) can encode video data captured at a local location for transmission to the other terminal via the network (150). Each terminal (130, 140) can also receive encoded video data transmitted by the other terminal, decode the encoded data, and display the recovered video data on a local display device.

In Figure 1, terminals (110 to 140) can be, for example, servers, personal computers and smartphones and/or any other type of terminal. For example, terminals (110 to 140) can be laptop computers, tablet computers, media players and/or dedicated video conferencing equipment. Network (150) refers to any number of networks that transmit encoded video data between terminals (110 to 140), including, for example, wired and/or wireless communication networks. Communication networks (150) can exchange data in circuit-switched and/or packet-switched channels. Representative networks include telecommunications networks, local area networks (LANs), wide area networks (WANs) and/or the Internet. For the purposes of this discussion, unless otherwise stated below, the architecture and topology of network (150) may be of little importance to the operation of this disclosure.

As an example of an application of the disclosed subject matter, Figure 2 illustrates the placement of a video encoder and decoder in a streaming environment. The disclosed subject matter can be used with other video-enabled applications, including, for example, video conferencing, digital TV, and storing compressed video on digital media including CDs, DVDs, memory sticks, etc.

As shown in Figure 2, the streaming system (200) may include a capture subsystem (213) comprising a video source (201) and an encoder (203). The streaming system (200) may also include at least one streaming server (205) and/or at least one streaming client (206).

A video source (201) can create, for example, an uncompressed video sample stream (202). The video source (201) can be, for example, a digital camera. The sample stream (202) is depicted as a thick line to emphasize the high data volume compared to the encoded video bitstream, and this sample stream (202) can be processed by an encoder (203) coupled to the camera (201). The encoder (203) can include hardware, software, or a combination thereof to implement or enforce aspects of the disclosed subject matter as described in more detail below. The encoder (203) can also generate an encoded video bitstream (204). The encoded video bitstream (204) is depicted as a thin line to emphasize the lower data volume compared to the uncompressed video sample stream (202), and it can be stored on a streaming server (205) for future use. One or more streaming clients (206) can access the streaming server (205) to retrieve a video bitstream (209) that can be used as a copy of the encoded video bitstream (204).

The streaming client (206) may include a video decoder (210) and a display (212). The video decoder (210) may, for example, decode an incoming video bitstream (209) as an encoded video bitstream (204) and create an outgoing video sample stream (211) that can be displayed on the display (212) or another presentation device (not depicted). In some streaming systems, the video bitstreams (204, 209) may be encoded according to certain video coding/compression standards. Examples of such standards include, but are not limited to, ITU-T Recommendation H.265. Video coding standards under development are informally referred to as Versatile Video Coding (VVC) standards. Implementations of this disclosure can be used in the context of VVC.

Figure 3 shows an example functional block diagram of a video decoder (210) attached to a display (212) according to an embodiment of the present disclosure.

The video decoder (210) may include a channel (312), a receiver (310), a buffer memory (315), an entropy decoder/parser (320), a scaler/inverse transform unit (351), an intra-frame prediction unit (352), a motion compensation prediction unit (353), an aggregator (355), a loop filter unit (356), a reference image memory (357), and a current image memory (358). In at least one embodiment, the video decoder (210) may include an integrated circuit, a series of integrated circuits, and/or other electronic circuits. The video decoder (210) may also be implemented, partially or entirely, in software running on one or more CPUs with associated memory.

In this and other embodiments, the receiver (310) may receive one or more encoded video sequences to be decoded by the decoder (210)—one encoded video sequence at a time, wherein the decoding of each encoded video sequence is independent of the decoding of other encoded video sequences. The encoded video sequences may be received from a channel (312), which may be a hardware/software link to a storage device storing the encoded video data. The receiver (310) 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 user entities (not depicted). The receiver (310) may separate the encoded video sequences from other data. To cope with network jitter, a buffer memory (315) may be coupled between the receiver (310) and the entropy decoder/parser (320) (hereinafter referred to as the "parser"). When the receiver (310) receives data from a store/forward device with sufficient bandwidth and controllability or from an isochronous synchronization network, the buffer (315) may not be used, or the buffer (315) may be small. In order to make the most of packet networks such as the Internet, a buffer (315) may be required, which can be relatively large and can have an adaptive size.

The video decoder (210) may include a parser (320) to reconstruct symbols (321) from the entropy-encoded video sequence. These symbols may include, for example, information for managing the operation of the decoder (210), and information for controlling a presentation device such as a display (212) that may be coupled to the decoder, as shown in FIG2. The control information for the presentation device may be in the form of Supplementary Enhancement Information (SEI) messages or fragments of Video Usability Information (VUI) parameter sets (not depicted). The parser (320) may perform parsing/entropy decoding on the received encoded video sequence. The encoding of the encoded video sequence may be based on video coding techniques or standards and may follow principles known to those skilled in the art, including: variable-length coding, Huffman coding, arithmetic coding with or without context sensitivity, etc. The parser (320) may extract a subgroup parameter set from the encoded video sequence for at least one subgroup of pixel subgroups in the video decoder based on at least one parameter corresponding to a group. Subgroups may include: Group of Pictures (GOP), pictures, tiles, slices, macroblocks, coding units (CU), blocks, transform units (TU), prediction units (PU), etc. The parser (320) can also extract information from the encoded video sequence, such as transform coefficients, quantizer parameter values, motion vectors, etc.

The parser (320) can perform entropy decoding/parsing operations on the video sequence received from the buffer (315) to create symbols (321).

Depending on the type of encoded video picture or portion thereof (e.g., inter-frame and intra-frame pictures, inter-frame and intra-frame blocks) and other factors, the reconstruction of the symbol (321) may involve multiple different units. Which units are involved and how they are involved can be controlled by subgroup control information parsed from the encoded video sequence by the parser (320). For brevity, the flow of this subgroup control information between the parser (320) and the aforementioned units is not depicted.

In addition to the functional blocks already mentioned, the decoder (210) can be conceptually subdivided into several functional units as described below. In a practical implementation operating under business constraints, many of these units interact closely with each other and can be at least partially integrated with one another. However, for the purposes of describing the disclosed subject matter, it is appropriate to conceptually subdivide it into the following functional units.

A unit can be a scaler/inverse transform unit (351). The scaler/inverse transform unit (351) can receive quantization transform coefficients as symbols (321) from the parser (320) and control information, including which transform method to use, block size, quantization factor, quantization scaling matrix, etc. The scaler/inverse transform unit (351) can output a block containing sample values that can be input into the aggregator (355).

In some cases, the output samples of the scaler/inverter unit (351) may belong to intra-coded blocks; that is, blocks that do not use predictive information from previously reconstructed images but can use predictive information from previously reconstructed portions of the current image. Such predictive information can be provided by the intra-picture prediction unit (352). In some cases, the intra-picture prediction unit (352) uses surrounding reconstructed information obtained from the current (partially reconstructed) image from the current image memory (358) to generate blocks of the same size and shape as the blocks in the reconstruction. In some cases, the aggregator 355 adds the predictive information already generated by the intra-picture prediction unit 352 to the output sample information provided by the scaler/inverter unit 351 on a per-sample basis.

In other cases, the output samples of the scaler/inverse transform unit (351) may belong to inter-frame encoded and possibly motion-compensated blocks. In such cases, the motion compensation prediction unit (353) can access the reference picture buffer (357) to obtain samples for prediction. After motion compensation of the obtained samples according to the symbols 321 belonging to the block, these samples can be added by the aggregator 355 to the output of the scaler/inverse transform unit 351 (referred to in this case as residual samples or residual signals) to generate output sample information. The address in the reference picture buffer (357) from which the motion compensation prediction unit (353) obtains the predicted samples can be controlled by motion vectors. Motion vectors can be used by the motion compensation prediction unit (353) in the form of symbols (321), 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 buffer (357) when using subsample precise motion vectors, motion vector prediction mechanisms, etc.

The output samples of the aggregator (355) can undergo various loop filtering techniques in the loop filter unit (356). The video compression technique may include in-loop filtering techniques, which are controlled by parameters included in the encoded video bitstream and available to the loop filter unit (356) as symbols (321) from the parser (320). However, the video compression technique may also respond to metadata obtained during the decoding of a previous (in decoding order) portion of an encoded picture or encoded video sequence, as well as to previously reconstructed and loop-filtered sample values.

The output of the loop filter unit (356) can be a sample stream, which can be output to a presentation device such as a display (212) and stored in a reference image buffer (357) for use in future inter-frame image prediction.

Once a certain encoded image has been fully reconstructed, it can be used as a reference image for future prediction. Once an encoded image has been fully reconstructed and the encoded image (by, for example, a parser (320)) is identified as a reference image, the current reference image stored in the current image memory (358) can become part of the reference image buffer (357), and a new current image memory can be reallocated before the reconstruction of subsequent encoded images begins.

The video decoder (210) can perform decoding operations according to a predetermined video compression technique that can be recorded in standards such as ITU-T Recommendation H.265. In the sense that the encoded video sequence follows the syntax of a video compression technique or standard, the encoded video sequence can conform to the syntax specified by the video compression technique or standard being used, as specified in the video compression technique document or standard, and specifically in the configuration file document therein. Furthermore, the complexity of the encoded video sequence can be within the range defined by the hierarchy of the video compression technique or standard in order to conform to some video compression techniques or standards. In some cases, the hierarchy limits the maximum image size, maximum frame rate, maximum reconstruction sample rate (measured, for example, megasamples per second), maximum reference image size, etc. In some cases, the limitations set by the hierarchy can be further limited by the hypothetical reference decoder (HRD) specification and the metadata managed by the HRD buffer, represented as a signal in the encoded video sequence.

In this implementation, the receiver (310) 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 (210) to properly decode the data and/or more accurately reconstruct the original video data. The additional data may be, for example, temporal, spatial, or SNR enhancement layers, redundant slices, redundant images, forward error correction codes, etc.

Figure 4 shows an example functional block diagram of a video encoder (203) associated with a video source (201) according to an embodiment of the present disclosure.

The video encoder (203) may include, for example, an encoder as a source encoder (430), an encoding engine (432), a (local) decoder (433), a reference image memory (434), a predictor (435), a transmitter (440), an entropy encoder (445), a controller (450), and a channel (460).

The encoder (203) can receive video samples from a video source (201) (which is not part of the encoder), which can capture video images to be encoded by the encoder (203).

The video source (201) can be provided as a digital video sample stream of a sequence of source videos to be encoded by the encoder (203). This digital video sample stream can have any suitable bit depth (e.g., x-bit, 10-bit, 12-bit, ...), any color space (e.g., BT.601YCrCb, RGB, ...), and any suitable sampling structure (e.g., YCrCb 4:2:0, YCrCb 4:4:4). In a media service system, the video source (201) can be a storage device storing previously prepared video. In a video conferencing system, the video source (203) can be a camera device capturing local image information as a video sequence. Video data can be provided as multiple individual pictures that are given motion when viewed sequentially. The pictures themselves can be organized as spatial pixel arrays, where each pixel can include one or more samples, depending on the sampling structure, color space, etc., used. Those skilled in the art will readily understand the relationship between pixels and samples. The following description focuses on samples.

According to the implementation, the encoder (203) can encode and compress images of the source video sequence into an encoded video sequence (443) in real time or under any other time constraints required by the application. Implementing an appropriate encoding speed can be a function of the controller (450). The controller (450) can also control other functional units as described below and can be functionally coupled to these units. Coupling is not depicted for simplicity. Parameters set by the controller (450) may include rate control related parameters (image skipping, quantizer, λ value of rate-distortion optimization techniques, etc.), image size, group of images (GOP) layout, maximum motion vector search range, etc. Other functions of the controller (450) can be readily identified by those skilled in the art and may belong to the video encoder (203) optimized for a particular system design.

Some video encoders operate in a manner readily recognizable to those skilled in the art as an "encoding loop." In a simplified description, an encoding loop may include the encoding portion of a source encoder (430) responsible for creating symbols based on the input picture and reference picture to be encoded, and a (local) decoder (433) embedded in the encoder (203), which, when compression between the symbols and the encoded video bitstream is lossless in some video compression techniques, reconstructs the symbols to create sample data that a (remote) decoder would also create. This reconstructed sample stream can be fed into a reference picture memory (434). Since decoding the symbol stream produces bit-accurate results independent of the decoder's location (local or remote), the contents of the reference picture memory are also bit-accurate between the local and remote encoders. In other words, the reference picture samples "seen" by the encoder's prediction portion are exactly the same sample values that the decoder would "see" during decoding using prediction. This fundamental principle of reference picture synchronization (and the drift that occurs, for example, when synchronization cannot be maintained due to channel errors) is known to those skilled in the art.

The operation of the “local” decoder (433) can be substantially the same as that of the “remote” decoder (210) which has been described in detail above in conjunction with Figure 3. However, since symbols are available and the entropy encoder (445) and parser (320) can losslessly encode/decode the symbols into an encoded video sequence, the entropy decoding part of the decoder (210), including the channel (312), receiver (310), buffer (315) and parser (320), does not need to be fully implemented in the local decoder (433).

It can be observed that any decoder technique other than parsing/entropy decoding, which exists in the decoder, may need to exist in the corresponding encoder in essentially the same functional form. For this reason, the subject matter presented focuses on decoder operation. Since encoder techniques can be inverses of the fully described decoder techniques, the description of encoder techniques can be simplified. More detailed descriptions will only be provided in certain places below.

As part of the operation of the source encoder (430), motion-compensated predictive coding can be performed, with reference to one or more previously encoded frames in the video sequence designated as "reference frames" to predictively encode the input frame. In this manner, the encoding engine (432) encodes the difference between pixel blocks of the input frame and pixel blocks of the reference frame that can be selected as the predictive reference for the input frame.

The local video decoder (433) can decode encoded video data of frames that can be designated as reference frames based on symbols created by the source encoder (430). The operation of the encoding engine (432) can advantageously be lossy. When the encoded video data is decoded at the video decoder (not shown in FIG. 4), the reconstructed video sequence can typically be a copy of the source video sequence with some errors. The local video decoder (433) replicates the decoding processing that can be performed on the reference frames by the video decoder, and can store the reconstructed reference frames in the reference picture memory (434). In this way, the encoder (203) can locally store copies of the reconstructed reference frames that share common content with the reconstructed reference frames that will be obtained by the remote video decoder (without transmission errors).

The predictor (435) can perform a prediction search against the encoding engine (432). That is, for a new frame to be encoded, the predictor (435) can search in the reference image memory (434) for sample data (as candidate reference pixel blocks) or specific metadata, such as reference image motion vectors, block shapes, etc., that can be used as appropriate prediction references for the new image. The predictor (435) can operate on a pixel-by-pixel basis based on the sample blocks to find appropriate prediction references. In some cases, the input image may have prediction references extracted from multiple reference images stored in the reference image memory (434), as determined by the search results obtained by the predictor (435).

The controller (450) can manage the encoding operations of the video encoder (430), including, for example, the settings of parameters and subgroup parameters used to encode video data.

The outputs of all the above-mentioned functional units can be entropy encoded in the entropy encoder (445). The entropy encoder converts the symbols generated by the various functional units into an encoded video sequence by performing lossless compression on the symbols according to techniques known to those skilled in the art, such as Huffman coding, variable-length coding, arithmetic coding, etc.

The transmitter (440) can buffer the encoded video sequence created by the entropy encoder (445) to prepare for transmission via a communication channel (460), which may be a hardware/software link to a storage device where the encoded video data will be stored. The transmitter (440) can combine the encoded video data from the video encoder (430) with other data to be transmitted, such as encoded audio data and/or auxiliary data streams (sources not shown).

The controller (450) can manage the operation of the encoder (203). During encoding, the controller (450) can assign a specific type of encoded picture to each encoded picture, which may affect the encoding technique that can be applied to the corresponding picture. For example, pictures can typically be assigned as intra-frame pictures (I-pictures), predictive pictures (P-pictures), or bidirectional predictive pictures (B-pictures).

An intra-frame picture (I-picture) can be an image that can be encoded and decoded without using any other frames in the sequence as a prediction source. Some video codecs allow different types of intra-frame pictures, including, for example, Independent Decoder Refresh (IDR) pictures. Those skilled in the art will understand these variations of I-pictures and their corresponding applications and characteristics.

A predictive image (P-image) can be an image that can be encoded and decoded using intra-frame prediction or inter-frame prediction, which uses at most one motion vector and reference index to predict sample values for each block.

Bidirectional predictive images (B-images) can be images that can be encoded and decoded using intra-frame prediction or inter-frame prediction, which uses at most two motion vectors and a reference index to predict sample values for each block. Similarly, multi-predictive images can use more than two reference images and associated metadata to reconstruct a single block.

Source images are typically spatially subdivided into multiple sample blocks (e.g., blocks with 4×4, 8×8, 4×8, or 16×16 samples respectively) and encoded block by block. These blocks can be predictively encoded with reference to other (already encoded) blocks, determined by coding assignments applied to the corresponding images of the blocks. For example, blocks of an I-image can be unpredictably encoded, or they can be predictively encoded (spatial or intra-frame prediction) with reference to already encoded blocks of the same image. Pixel blocks of a P-image can be unpredictably encoded with reference to a previously encoded reference image via spatial or temporal prediction. Blocks of a B-image can be unpredictably encoded with reference to one or two previously encoded reference images via spatial or temporal prediction.

The video encoder (203) can perform encoding operations according to a predetermined video coding technique or standard, such as ITU-T H.265 Recommendation. In operation, the video encoder (203) can perform various compression operations, including predictive coding operations that utilize temporal and spatial redundancy in the input video sequence. Therefore, the encoded video data can conform to the syntax specified by the video coding technique or standard used.

In this implementation, the transmitter (440) may transmit additional data along with the encoded video. The video encoder (430) 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 images and slices, supplementary enhancement information (SEI) messages, fragments of visual usability information (VUI) parameter sets, etc.

Figure 6 is a diagram of the intra-prediction mode in VVC draft 2.

In VVC draft 2, there are a total of 87 intra-prediction modes as shown in Figure 5. Mode 18 (601) is a horizontal mode, mode 50 (602) is a vertical mode, and modes 2 (603), 34 (604), and 66 (605) are diagonal modes. Modes -1 to -10 and modes 67 to 76 are referred to as Wide-Angle Intra Prediction (WAIP) modes (606, 707).

In VVC Draft 2, the size of the MPM list remains 3, and the MPM list generation process is the same as in HEVC. However, the difference lies in the fact that, since there are 67 modes represented by signals in VVC Draft 2, "offset" is changed to 61 and "mod" is changed to 64.

The following clause in VVC Draft 2 describes the luma intra-frame mode coding process, in which IntraPredModeY[xPb][yPb] is derived:

1. Set the adjacent positions (xNbA, yNbA) and (xNbB, yNbB) to be equal to (xPb-1, yPb) and (xPb, yPb-1) respectively.

2. For X replaced by A or B, derive the variable candIntraPredModeX using the following steps:

- The availability checking process for blocks specified in Clause 6.4.X [Ed.(BB): Neighbouring blocks availability checking process tbd] is invoked, where the position (xCurr, yCurr) is set to equal to (xPb, yPb) and the adjacent position (xNbY, yNbY) is set to equal to (xNbX, yNbX) as input, and the output is assigned to availableX.

- Obtain the candidate intra-prediction mode candIntraPredModeX by following these steps:

- If one or more of the following conditions are true, then set candIntraPredModeX to be equal to INTRA_DC.

- The variable availableX is equal to FALSE.

-CuPredMode[xNbX][yNbX] is not equal to MODE_INTRA.

-X equals B and yPb-1 is less than ((yPb>>CtbLog2SizeY)<<CtbLog2SizeY).

- Otherwise, set candIntraPredModeX to be equal to IntraPredModeY[xNbX][yNbX].

3. Obtain candModeList[x] by following these steps, where x = 0...2:

- If candIntraPredModeB equals candIntraPredModeA, then the following processing applies:

- If candIntraPredModeA is less than 2 (i.e., equal to INTRA_PLANAR or INTRA_DC), then derive candModeList[x] as follows, where x = 0..2:

candModeList[0]＝INTRA_PLANAR (8-1)

candModeList[1]＝INTRA_DC (8-2)

candModeList[2]＝INTRA_ANGULAR50 (8-3)

- Otherwise, obtain candModeList[x] using the following steps, where x = 0..2:

candModeList[0]＝candIntraPredModeA (8-4)

candModeList[1]＝2+((candIntraPredModeA+61)%64) (8-5)

candModeList[2]＝2+((candIntraPredModeA-1)%64) (8-6)

- Otherwise (candIntraPredModeB is not equal to candIntraPredModeA), the following processing applies:

- Obtain candModeList[0] and candModeList[1] by following these steps:

candModeList[0]＝candIntraPredModeA                    (8-7)

candModeList[1]＝candIntraPredModeB                    (8-8)

- If neither candModeList[0] nor candModeList[1] is equal to INTRA_PLANAR, then set candModeList[2] to be equal to INTRA_PLANAR.

Otherwise, if neither candModeList[0] nor candModeList[1] is equal to INTRA_DC, then set candModeList[2] to be equal to INTRA_DC.

- Otherwise, set candModeList[2] to be equal to INTRA_ANGULAR50.

4. Obtain IntraPredModeY[xPb][yPb] by applying the following procedure:

- If intra_luma_mpm_flag[xPb][yPb] equals 1, then set IntraPredModeY[xPb][yPb] to equal candModeList[intra_luma_mpm_idx[xPb][yPb]].

- Otherwise, IntraPredModeY[xPb][yPb] is obtained by applying the following ordered steps:

1. Modify the array candModeList[x] in the following ordered steps, where x = 0..2:

i. If candModeList[0] is greater than candModeList[1], swap the two values as follows:

(candModeList[0],candModeList[1])＝Swap(candModeList[0],candModeList[1])      (8-9)

ii. If candModeList[0] is greater than candModeList[2], swap the two values as follows:

(candModeList[0],candModeList[2])＝Swap(candModeList[0],candModeList[2])     (8-10)

iii. If candModeList[1] is greater than candModeList[2], swap the two values as follows:

(candModeList[1],candModeList[2])＝Swap(candModeList[1],candModeList[2])      (8-11)

2. Obtain IntraPredModeY[xPb][yPb] through the following ordered steps:

i. Set IntraPredModeY[xPb][yPb] to be equal to intra_luma_mpm_remainder[xPb][yPb].

ii. For i equal to 0 to 2, inclusive, if IntraPredModeY[xPb][yPb] is greater than or equal to candModeList[i], increment the value of IntraPredModeY[xPb][yPb] by 1.

In the above, the variable IntraPredModeY[x][y], where x = xPb..xPb+cbWidth-1 and y = yPb..yPb+cbHeight-1, is set to be equal to IntraPredModeY[xPb][yPb].

In the development of VVC draft 2, a list of MPMs of size 6 was proposed. This list of MPMs includes a Planar mode and a DC mode. The remaining 4 MPMs are generated using two adjacent modes, the left mode and the top mode.

Multi-line intra-prediction is proposed to utilize more reference lines for intra-prediction. The encoder determines and signals which reference line to use to generate the intra-predictor. The reference line index is signaled before the intra-prediction mode, and the Planar/DC mode is excluded from the intra-prediction mode if a non-zero reference line index is signaled. Figure 7 depicts an example of four reference lines (710), where each reference line (710) consists of six segments (i.e., segments A to F) along with a reference sample at the upper left. Furthermore, segments A and F are filled with samples closest to segments B and E, respectively.

In multi-line intra-frame prediction, Planar and DC modes are excluded from MPM list generation and mode encoding when the reference line index transmitted by the signal is non-zero. Furthermore, it has been proposed that an MPM list of size 6 can be generated using only two adjacent modes. Therefore, how to generate 6 angle MPMs for non-zero lines when only two adjacent modes are accessible remains an open problem.

The proposed methods can be used alone or in any combination in any order.

In the following description, the row index of the most recent reference row is 0 (zero reference row). The largest reference row number transmitted by signal is denoted as N.

As shown in Figure 8, the upper (top) side block (701) and the left side block (702) are defined in the following manner:

As shown in Figure 8, the pixel at the top left position within the current block (703) is represented as (x, y). A block whose y-coordinates of all included samples are greater than or equal to y and whose x-coordinates of all included samples are less than x is called the left block. A block whose y-coordinates of all included samples are less than y is called the top block. Figure 8 shows an example of the left blocks (L1, Lx, and Ln) and top blocks (A1, A2, Ax, and An) of the current block (703).

The two adjacent patterns mentioned below can originate from either the top (701) or the left (702) of the current block (703). Here are some examples of two adjacent patterns:

In one example, both adjacent patterns come from the left (702).

In another example, both adjacent patterns originate from the top (701).

In another example, one of the adjacent patterns comes from the left (702), while the other adjacent pattern comes from the top (701).

In another example, if the width of the current block (703) is greater than the height of the current block (703), both adjacent patterns come from the top (701), or if the height is greater than the width, both adjacent patterns come from the left (702), or if the width is equal to the height, one adjacent pattern comes from the top (701) and the other adjacent pattern comes from the left (702).

Reference sample sides (as described in the examples above) can be selected and used based on block width, block height, and the ratio of block width to block height to derive two (or more) adjacent blocks.

In one example, if the block width/height is greater than a predefined threshold, only two (or more) adjacent blocks are selected from the top (701). Example values for the threshold include, but are not limited to, 2, 4, 8, 16, 32, and 64.

In another example, if the block height/width is greater than a predefined threshold, only two (or more) adjacent blocks are selected from the left (702). Example values for the threshold include, but are not limited to, 2, 4, 8, 16, 32, and 64.

In the following description, if the mode of an adjacent block is not available, the mode will be set to Planar mode or DC mode.

In the following description, if the pattern number represented by the signal ranges from 0 to M (0 and M inclusive), then M can be any positive integer, such as 34 or 66. The neighboring patterns of a given pattern X are defined as follows: if X is greater than 2 and less than M-1, then the neighboring patterns of X are X-1 and X+1. If X equals 2, then the neighboring patterns of X are 3 and M (or M-1). If X equals M-1, then the neighboring patterns of X are X-1 and X+1 (or 2). If X equals M, then the neighboring patterns of X are M-1 and 2 (or 3).

In the following description, if a mode is not a Planar mode or a DC mode, or if a mode generates prediction samples based on a given prediction direction, such as intra-prediction modes 2 to 66 as defined in VVC Draft 2, then the mode is referred to as an angular mode. The variables offset and mod can have the following two sets:

1) Offset=mod-3, mod=M-2;

2) Offset=mod-3, mod=M-1;

When the reference row index, represented by a signal, is non-zero, the following method can generate 6-angle MPMs via two adjacent patterns. The following methods or examples can be used individually or in any combination in any order.

In one implementation, if at least one of two adjacent patterns is an angular pattern, then six angular MPMs are generated using the following algorithm. The two adjacent patterns are denoted as Mode_A and Mode_B. The variable ang_mode[] is used to record the angular patterns of the adjacent patterns. The variable ang_count is used to indicate the number of angular patterns, and the variable mpm_index is used to indicate the index of the MPM list. Initially, ang_count and mpm_index are set to 0. IncludedMode[] is used to indicate whether each pattern is included in the MPM list, and all elements in the includedMode[] array are initially set to false.

●If Mode_A is angle mode, then MPM[mpm_index] = Mode_A, ang_count += 1, mpm_index += 1;

●If Mode_B is the angle mode, then MPM[mpm_index] = Mode_B, ang_count += 1, mpm_index += 1;

●For (diff=0;diff<=2&&mpm_index<6;diff++){

●For (idx = 0; idx < ang_count; idx++){

○MPM[mpm_index]=((ang_mode[idx]+offset-diff)%mod)+2;

○If (includedMode[MPM[mpm_index]] == false)){

■includedMode[MPM[mpm_index++]]=true}

○ If mpm_index == 6, then exit the loop;

○MPM[mpm_index]=((ang_mode[idx]-1+diff)%mod)+2;

○If (includedMode[MPM[mpm_index]] == false){

■includedMode[MPM[mpm_index++]]=true}

In one implementation, if only one of the adjacent patterns is an angular pattern—denoted as ang_neighbor—then ang_neighbor and its two neighboring patterns (denoted as mode_L and mode_R) are added to the MPM list, and then one neighboring pattern of mode_L and one neighboring pattern of mode_R are added to the MPM list. Finally, vertical/horizontal patterns are added to generate six angular MPMs. These six angular patterns can be added to the MPM list in any order.

● In one example, six angle MPMs are generated as follows.

●MPM[0]＝ang_mode

●MPM[1]=((ang_mode+offset)%mod)+2;

●MPM[2]=((ang_mode-1)%mod)+2;

●MPM[3]=((ang_mode-1+offset)%mod)+2;

●MPM[4]=((ang_mode)%mod)+2;

●MPM[5] = Vertical or Horizontal mode. In one example, if MPM[0]

If vertical mode is not included in MPM[4], then MPM[5] is set to vertical mode.

Otherwise, MPM[5] is set to horizontal mode.

In another implementation, if only one of the adjacent patterns is an angular pattern—denoted as ang_neighbor—then ang_neighbor and its two neighboring patterns (denoted as mode_L and mode_R) are added to the MPM list. Then, one neighboring pattern of mode_L (denoted as mode_L_L) and one neighboring pattern of mode_R (denoted as mode_R_R) are added to the MPM list. Finally, one neighboring pattern of either mode_L_L or mode_R_R is added to the MPM list. These six angular patterns can be added to the MPM list in any order.

● In one example, six angle MPMs are generated as follows.

●MPM[0]＝ang_mode

●MPM[1]=((ang_mode+offset)%mod)+2;

●MPM[2]=((ang_mode-1)%mod)+2;

●MPM[3]=((ang_mode-1+offset)%mod)+2;

●MPM[4]=((ang_mode)%mod)+2;

●MPM[5]=((ang_mode+1)%mod)+2;

● In another example, six angle MPMs are generated as follows.

●MPM[0]＝ang_mode

●MPM[1]=((ang_mode+offset)%mod)+2;

●MPM[2]=((ang_mode-1)%mod)+2;

●MPM[3]=((ang_mode-1+offset)%mod)+2;

●MPM[4]=((ang_mode)%mod)+2;

●MPM[5]=((ang_mode-2+offset)%mod)+2;

In another implementation, if only one of the adjacent patterns is an angular pattern—represented as ang_neighbor—then six angular MPMs are obtained as follows, wherein these six angular patterns can be added to the MPM list in any order. An example is shown below.

●MPM[0]＝ang_mode

●MPM[1]=((ang_mode+offset)%mod)+2;

●MPM[2]=((ang_mode-1)%mod)+2;

●MPM[3]=((ang_mode-2+offset)%mod)+2;

●MPM[4]=((ang_mode+1)%mod)+2;

● MPM[5] = Vertical or Horizontal mode. In one example, if vertical mode is not included among MPM[0] to MPM[4], then MPM[5] is set to vertical mode. Otherwise, MPM[5] is set to horizontal mode.

In another implementation, if two adjacent modes in the adjacent patterns are angular modes and they are neighboring modes, the MPM list can be generated as follows: Two adjacent modes are represented as Mode_A and Mode_B, and they are added to the MPM list. The variables ang_max and ang_min are used to record the maximum and minimum modes between Mode_A and Mode_B.

● If Mode_A is greater than Mode_B, then ang_max is set to Mode_A and ang_min is set to Mode_B.

● If ang_min equals 2 and ang_max equals M-1 or M, then swap the values of ang_min and ang_max.

●Derive the remaining four angle MPMs as follows. These four patterns can be added in any order; an example is provided below.

●MPM[2]=((ang_min+offset)%mod)+2;

●MPM[3]=((ang_max-1)%mod)+2;

●MPM[4]=((ang_min-1+offset)%mod)+2;

●MPM[5]=((ang_max)%mod)+2;

In another implementation, two adjacent modes are represented by Mode_A and Mode_B, and if both adjacent modes are angular modes and abs(Mode_A-Mode_B)>2&&abs(Mode_A-Mode_B)<＝Thres, then the following algorithm is used to generate 6 angular MPMs. Thres is a positive integer, and Thres is greater than 2, for example, Thres=61 or 62 or 63.

● First, add Mode_A and Mode_B to the MPM list.

●Then, add the two neighboring modes of Mode_A and the two neighboring modes of Mode_B to the MPM list.

●And these 6 angle MPMs can be added to the MPM list in any order.

●The following shows examples of generating 6 MPMs.

○MPM[0]＝Mode_A

○MPM[1]＝Mode_B

○MPM[2]=((Mode_A+offset)%mod)+2;

○MPM[3]=((Mode_A-1)%mod)+2;

○MPM[4]=((Mode_B+offset)%mod)+2;

○MPM[5]=((Mode_B-1)%mod)+2;

In another implementation, two adjacent modes are represented by Mode_A and Mode_B, and if both adjacent modes are angle modes, and abs(Mode_A-Mode_B)＝＝2||abs(Mode_A-Mode_B)>Thres, where Thres is a positive integer and Thres is greater than 2, for example Thres＝61 or 62 or 63, then 6 angle MPMs are obtained by the following algorithm.

● Use the variables ang_max and ang_min to record the maximum and minimum modes between Mode_A and Mode_B.

● If Mode_A is greater than Mode_B, then ang_max is set to Mode_A and ang_min is set to Mode_B.

●Then, add the three neighboring modes of Mode_A and Mode_B to the MPM list.

● Finally, add the vertical or horizontal pattern to the MPM list, and these 6 MPMs can be added to the MPM list in any order.

●An example is shown below.

●MPM[0]＝ang_min

●MPM[1]＝ang_max

●MPM[2]=((ang_min-1)%mod)+2;

●MPM[3]=((ang_min+offset)%mod)+2;

MPM[4]=((ang_max-1)%mod)+2;

●MPM[5] = Vertical or Horizontal mode. In one example, if MPM[0]

If vertical mode is not included in MPM[4], then MPM[5] is set to vertical mode.

Otherwise, MPM[5] is set to horizontal mode.

In another implementation, if two adjacent modes are both Planar or DC modes, then six default modes are used to populate the MPM list. These six default modes can be added to the MPM list in any order.

● In one implementation, the six default modes are {50, 18, 2, 34, 66, 26}.

●In another implementation, the six default modes are {50, 18, 2, 34, 26, 42}.

●In another implementation, when the width of the current block is greater than its height, the six default patterns are {50, 18, 34, 66, 42, 58}.

●In another implementation, when the height of the current block is greater than its width, the six default patterns are {50, 18, 34, 2, 10, 26}.

●In another implementation, when the width of the current block equals its height, the six default patterns are {50, 18, 2, 34, 26, 42}.

In another implementation, all adjacent modes of the angle mode are first added to the MPM list. Then, for each of these adjacent modes, denoted as ang_mode, if angle mode ((ang_mode-1)%mod)+2 and angle mode ((ang_mode+offset)%mod)+2 are not included in the MPM list, they are added to the MPM list.

● In one implementation, if the MPM list is still not completely filled, several default modes are added. The list of default modes can be any of the alternative selections described in item number h above.

● In another implementation, if the MPM list is still not completely filled, for each mode (denoted as mpm_mode) that is already in the MPM list, if the angle mode ((mpm_mode-1)%mod)+2 and the angle mode ((mpm_mode+offset)%mod)+2 are not included in the MPM list, then they are added to the MPM list.

In at least one embodiment, the above-described technology can be implemented by an integrated circuit, a series of integrated circuits, and/or other electronic circuits. In at least one embodiment, the technology can be partially or completely implemented in software running on one or more CPUs with associated memory.

The above-described techniques can be implemented as computer software using computer-readable instructions and physically stored in one or more computer-readable media. For example, Figure 9 illustrates a computer system (800) suitable for implementing certain embodiments of the present disclosure.

Computer software can be encoded using any suitable machine code or computer language. Mechanisms such as assembly, compilation, and linking can be applied to computer software to create code containing instructions, which can be executed directly by the computer's central processing unit (CPU), graphics processing unit (GPU), or through interpretation, microcode execution, etc.

The instructions can be executed on various types of computers or their components, including, for example, personal computers, tablet computers, servers, smartphones, gaming devices, Internet of Things devices, etc.

The components for the computer system (800) shown in Figure 9 are exemplary in nature and are not intended to impose any limitation on the scope or functionality of computer software implementing embodiments of this disclosure. The configuration of the components should also not be construed as having any dependency or requirement relating to any one or a combination of components shown in a non-limiting embodiment of the computer system (800).

The computer system (800) may include certain human-machine interface input devices. Such human-machine interface input devices can respond to input from one or more human users via, for example, tactile input (e.g., keystrokes, swipes, data glove movements), audio input (e.g., voice, clapping), visual input (e.g., gestures), and olfactory input (not depicted). The human-machine interface devices can also be used to capture certain media that are not necessarily directly related to conscious human input, such as audio (e.g., speech, music, ambient sounds), images (e.g., scanned images, photographic images obtained from still image capturing devices), and video (e.g., two-dimensional video, three-dimensional video including stereoscopic video).

The input human-machine interface device may include one or more of the following (only one of each is depicted): keyboard (801), mouse (802), touchpad (803), touch screen (810), data glove, joystick (805), microphone (806), scanner (807), and camera device (808).

The computer system (800) may also include certain human-machine interface output devices. Such human-machine interface output devices may stimulate the senses of one or more human users 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 provided by a touchscreen (810), data gloves, or joystick (805), but tactile feedback devices that are not used as input devices may also exist). For example, such devices may be audio output devices (e.g., speakers (809), headphones (not depicted)), visual output devices (e.g., screens (810), including CRT screens, LCD screens, plasma screens, OLED screens, each with or without touchscreen input capability, each with or without tactile feedback capability—some of which may be able to output two-dimensional visual output or more than three-dimensional output by means such as stereoscopic output; virtual reality glasses (not depicted), holographic displays, and smoke boxes (not depicted)), and printers (not depicted).

The computer system (800) may also include human-accessible storage devices and their associated media, such as optical media including CD/DVD ROM/RW (820) having media such as CD/DVD (821), thumb drives (822), removable hard disk drives or solid-state drives (823), conventional magnetic media such as magnetic tapes and floppy disks (not depicted), devices based on dedicated ROM/ASIC/PLD such as security dongles (not depicted), etc.

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

The computer system (800) may also include interfaces to one or more communication networks. These networks may be, for example, wireless, wired, or optical. They may also be local, wide-area, metropolitan, vehicular, and industrial, real-time, latency-tolerant, etc. Examples of networks include local area networks such as Ethernet, wireless LANs, cellular networks (including GSM, 3G, 4G, 5G, LTE, etc.), cable or wireless wide-area digital television networks (including cable television, satellite television, and terrestrial broadcast television), vehicular and industrial networks (including CANbus), etc. Some networks typically require external network interface adapters attached to certain general-purpose data ports or peripheral buses (849) (such as, for example, a USB port of the computer system (800)); other interfaces are typically integrated into the core of the computer system (800) by attaching to system buses as described below (e.g., an Ethernet interface integrated into a PC computer system or a cellular network interface integrated into a smartphone computer system). Using any of these networks, the computer system (800) can communicate with other entities. Such communication can be unidirectional, receive-only (e.g., broadcast television), send-only (e.g., to a CANBus device), or bidirectional, such as using a local area digital network or a wide area digital network to other computer systems. Certain protocols and protocol stacks can be used on each of these networks and network interfaces as described above.

The aforementioned human-machine interface device, human-accessible storage device, and network interface can be attached to the core (840) of the computer system (800).

The core (840) may include one or more central processing units (CPUs) (841), graphics processing units (GPUs) (842), dedicated programmable processing units in the form of field-programmable gate arrays (FPGAs) (843), hardware accelerators (844) for certain tasks, etc. These devices, along with read-only memory (ROM) (845), random access memory (846), and internal mass storage devices such as internal non-user-accessible hard disk drives, SSDs, etc. (847), can be connected via a system bus (848). In some computer systems, the system bus (848) can be accessed in the form of one or more physical connectors to allow for expansion with additional CPUs, GPUs, etc. Peripheral devices may be attached directly or via a peripheral bus (849) to the core's system bus (848). Peripheral bus architectures include PCI, USB, etc.

The CPU (841), GPU (842), FPGA (843), and accelerator (844) can execute certain instructions that, when combined, constitute the aforementioned computer code. This computer code can be stored in ROM (845) or RAM (846). Transient data can also be stored in RAM (846), while permanent data can be stored, for example, in an internal mass storage device (847). Fast storage and retrieval of any memory device within the memory device can be achieved by using a cache memory, which can be closely associated with one or more CPUs (841), GPUs (842), mass storage devices (847), ROMs (845), RAMs (846), etc.

Computer-readable media may contain computer code for performing operations of various computer implementations. The media and computer code may be specifically designed and constructed for the purposes of this disclosure, or they may be of a type known and available to those skilled in the art of computer software.

By way of example and not limitation, a computer system (800) with an architecture—and in particular a core (840)—can be functionalized by a processor (including a CPU, GPU, FPGA, accelerator, etc.) executing software embodied in one or more tangible computer-readable media. Such computer-readable media can be media associated with user-accessible mass storage devices as described above, as well as certain storage devices of the core (840) having non-transitory characteristics, such as in-core mass storage (847) or ROM (845). Software implementing various embodiments of this disclosure can be stored in such devices and executed by the core (840). Depending on specific needs, the computer-readable medium may include one or more memory devices or chips. The software can cause the core (840)—and in particular the processors therein (including CPUs, GPUs, FPGAs, etc.)—to execute specific processes or specific portions of specific processes described herein, including defining data structures stored in RAM (846) and modifying these data structures according to the processes defined by the software. Alternatively or as an alternative, a computer system may be provided with functionality by hard-wired or otherwise embodied logic in circuitry (e.g., an accelerator (844)), which may replace or operate 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 a computer-readable medium may include circuitry (e.g., an integrated circuit (IC)) storing software for execution, circuitry embodying logic for execution, or both. This disclosure includes any suitable combination of hardware and software.

Although several non-limiting embodiments have been described in this disclosure, there are changes, substitutions, and various equivalent alternatives that fall within the scope of this disclosure. Therefore, it will be understood 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 this disclosure and thus its spirit and scope.

Claims (15)

1. A video decoding method, characterized in that it includes: Obtain the intra-prediction mode of the first neighboring block of the current block; Obtain the intra-prediction mode of the second adjacent block of the current block; and When the intra-prediction mode of the first adjacent block and the intra-prediction mode of the second adjacent block are both angle modes, and are adjacent angle modes, the most probable mode (MPM) list is obtained according to the size relationship between the intra-prediction modes of the first adjacent block and the intra-prediction modes of the second adjacent block. The MPM list includes multiple candidate modes for intra-prediction of the current block. The first candidate mode of the MPM list is determined as the intra-prediction mode of the first adjacent block; and The second candidate mode of the MPM list is determined as the intra-prediction mode of the second adjacent block. 2. The video decoding method according to claim 1, characterized in that it further comprises: Based on the index value, the relationship between the angle modes of the intra-prediction modes of the first adjacent block and the intra-prediction modes of the second adjacent block is determined, wherein the angle mode with the smaller index value is the first mode and the angle mode with the larger index value is the second mode. 3. The video decoding method according to claim 2, characterized in that it further comprises: The third candidate mode of the MPM list is determined as the second neighboring angle mode of the first mode, and the second neighboring angle mode of the first mode has a value that is not between the first mode and the second mode; The fourth candidate mode of the MPM list is determined as the second neighboring angle mode of the second mode, and the second neighboring angle mode of the second mode has a value that is not between the first mode and the second mode; The fifth candidate mode in the MPM list is determined to be the neighboring angle mode of the second neighboring angle mode of the first mode, excluding the first mode. 4. The video decoding method according to claim 1, wherein obtaining the most probable mode (MPM) list includes: Add Mode_A and Mode_B to the MPM list; and The remaining angle modes in the MPM list are determined as follows: MPM[2]=((ang_min+offset)%mod)+2 MPM[3]=((ang_max-1)%mod)+2 MPM[4]=((ang_min-1+offset)%mod)+2 Wherein, Mode_A and Mode_B represent the intra-prediction mode of the first adjacent block and the intra-prediction mode of the second adjacent block, respectively, and the variables ang_max and ang_min are used to record the maximum and minimum modes between Mode_A and Mode_B. If Mode_A is greater than Mode_B, then set ang_max to Mode_A and ang_min to Mode_B; If ang_min equals 2 and ang_max equals M-1 or M, then the values of ang_min and ang_max are switched. The mode number represented by the signal ranges from 0 to M, including 0 and M. The variable offset = mod-3, the variable mod = M-–2, and M is 34 or 66. 5. A video encoding method, characterized in that it includes: Set the intra-prediction mode of the first adjacent block of the current block; Set the intra-prediction mode of the second adjacent block of the current block; and When the intra-prediction mode of the first adjacent block and the intra-prediction mode of the second adjacent block are both angle modes, and are adjacent angle modes, a most probable mode (MPM) list is generated based on the size relationship between the intra-prediction modes of the first adjacent block and the intra-prediction modes of the second adjacent block. The MPM list includes multiple candidate modes for intra-prediction of the current block. Set the first candidate mode of the MPM list to the intra-prediction mode of the first adjacent block; and Set the second candidate mode of the MPM list as the intra-prediction mode of the second adjacent block. 6. The video encoding method according to claim 5, characterized in that it further comprises: Based on the index value, the relationship between the angle modes of the intra-prediction modes of the first adjacent block and the intra-prediction modes of the second adjacent block is determined, wherein the angle mode with the smaller index value is the first mode and the angle mode with the larger index value is the second mode. 7. The video encoding method according to claim 6, characterized in that it further comprises: The third candidate mode of the MPM list is set as the second neighboring angle mode of the first mode, and the second neighboring angle mode of the first mode has a value that is not between the first mode and the second mode; The fourth candidate mode of the MPM list is set as the second neighboring angle mode of the second mode, and the second neighboring angle mode of the second mode has a value that is not between the first mode and the second mode; The fifth candidate mode of the MPM list is set to the neighboring angle mode of the second neighboring angle mode of the first mode, excluding the first mode. 8. The video encoding method according to claim 5, wherein generating the most probable mode (MPM) list comprises: Add Mode_A and Mode_B to the MPM list; and The remaining angle modes in the MPM list are determined as follows: MPM[2]=((ang_min+offset)%mod)+2 MPM[3]=((ang_max-1)%mod)+2 MPM[4]=((ang_min-1+offset)%mod)+2 Wherein, Mode_A and Mode_B represent the intra-prediction mode of the first adjacent block and the intra-prediction mode of the second adjacent block, respectively, and the variables ang_max and ang_min are used to record the maximum and minimum modes between Mode_A and Mode_B. If Mode_A is greater than Mode_B, then set ang_max to Mode_A and ang_min to Mode_B; If ang_min equals 2 and ang_max equals M-1 or M, then the values of ang_min and ang_max are switched. The mode number represented by the signal ranges from 0 to M, including 0 and M. The variable offset = mod-3, the variable mod = M-–2, and M is 34 or 66. 9. A video decoding apparatus, characterized in that the apparatus comprises an acquisition unit and a generation unit: The acquisition unit is configured to acquire the intra-prediction mode of the first adjacent block of the current block and the intra-prediction mode of the second adjacent block of the current block; and The generation unit is configured to obtain a most probable mode (MPM) list based on the size relationship between the intra-prediction modes of the first adjacent block and the intra-prediction modes of the second adjacent block when both the intra-prediction modes of the first adjacent block and the intra-prediction modes of the second adjacent block are angle modes and are adjacent angle modes. The MPM list includes multiple candidate modes for intra-prediction of the current block. The first candidate mode of the MPM list is determined as the intra-prediction mode of the first adjacent block; and The second candidate mode of the MPM list is determined as the intra-prediction mode of the second adjacent block. 10. A video encoding apparatus, characterized in that the apparatus comprises an acquisition unit and a generation unit: The acquisition unit is configured to set the intra-prediction mode of the first adjacent block of the current block and the intra-prediction mode of the second adjacent block of the current block; and The generation unit is configured to generate a most probable mode (MPM) list based on the size relationship between the intra-prediction modes of the first adjacent block and the intra-prediction modes of the second adjacent block when both the intra-prediction modes of the first adjacent block and the intra-prediction modes of the second adjacent block are angle modes and are adjacent angle modes. The MPM list includes multiple candidate modes for intra-prediction of the current block. Set the first candidate mode of the MPM list to the intra-prediction mode of the first adjacent block; and Set the second candidate mode of the MPM list as the intra-prediction mode of the second adjacent block. 11. A non-transitory computer-readable storage medium for storing instructions, wherein the instructions cause at least one processor to perform the method as described in any one of claims 1-8. 12. 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 as described in any one of claims 1-8 according to the instructions in the program code. 13. A method for storing a bitstream, characterized in that the video encoding method according to any one of claims 5-8 is performed to generate the bitstream, and the bitstream is stored. 14. A method for transmitting a bit stream, characterized in that the video encoding method according to any one of claims 5-8 is performed to generate the bit stream, and the bit stream is transmitted. 15. A computer storage medium, characterized in that it stores instructions executable by at least one processor to perform the method of any one of claims 5-8, generating and storing a video bitstream.