Video encoding method, apparatus, device, and computer-readable storage medium

Abstract

Aspects of the present disclosure provide methods and apparatuses for video coding. In some examples, an apparatus for video coding includes processing circuitry. The processing circuitry obtains prediction information of a current block in a current picture of a video sequence, the prediction information indicating a first prediction mode for the current block. The processing circuitry determines whether an adjacent block adjacent to and encoded before the current block uses the first prediction mode. Then, in response to determining that the adjacent block uses the first prediction mode, the processing circuitry inserts the prediction information from the adjacent block into a prediction list for the first prediction mode. Finally, the processing circuitry encodes the current block according to the prediction list for the first prediction mode.

Description

[0001] This application is a divisional application of an actively amended version of the patent application with the filing date of January 6, 2020, the Chinese patent application number of 202080012655.4, and the invention title of "Method and Apparatus for Video Decoding, Computer Equipment, and Storage Medium". Technical Field

[0002] The present disclosure describes embodiments generally related to video coding. Background Art

[0003] The background description provided herein is for the purpose of generally presenting the content of the present disclosure. The extent to which the work of the currently named inventors described in this background art section and various aspects of this specification has been carried out does not indicate that it was prior art at the time of filing of this application, and it has never been expressly or implicitly admitted as prior art of this application.

[0004] Inter-picture prediction with motion compensation can be used to perform video coding and decoding. Uncompressed digital video can include a series of pictures, each picture having a spatial size of, for example, 1920×1080 luminance samples and associated chrominance samples. The series of pictures can have a fixed or variable picture rate (also informally referred to as frame rate), such as 60 pictures per second or 60 Hz. Uncompressed video has a high bit rate requirement. For example, a 1080p60 4:2:0 video (1920×1080 luminance sample resolution at 60 Hz frame rate) with 8 bits per sample requires a bandwidth of nearly 1.5 Gbit / s. An hour of such video requires more than 600 GB of storage space.

[0005] One purpose of video coding and decoding can be to reduce redundancy in the input video signal through compression. Compression can help reduce the above-mentioned bandwidth or storage space requirements, which can be reduced by two or more orders of magnitude in some cases. Lossless compression and lossy compression, as well as their combinations, can be employed. Lossless compression refers to a technique in which an exact copy of the original signal can be reconstructed from 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 such that the reconstructed signal can be used for the intended application. In the case of video, lossy compression is widely used. The amount of tolerable distortion depends on the application. For example, users of some consumer streaming applications can tolerate higher distortion compared to users of television distribution applications. The achievable compression ratio can reflect that higher allowable / acceptable distortion can result in a higher compression ratio.

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

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

[0008] Traditional intra coding (such as intra coding known from, for example, MPEG-2 generation coding techniques) does not use intra prediction. However, some newer video compression techniques include techniques that attempt from, for example, surrounding sample data and / or metadata, which are data blocks that are spatially adjacent and obtained during the encoding / decoding of data blocks that are earlier in the decoding order. Such techniques are hereafter referred to as "intra prediction" techniques. It should be noted that, in at least some cases, intra prediction uses only reference data from the currently reconstructed picture and not reference data from reference pictures.

[0009] There can be many different forms of intra prediction. When more than one such technique can be used in a given video coding technique, the techniques used can be coded in intra prediction mode. In some cases, a mode can have multiple sub-modes and / or multiple parameters, and these sub-modes and parameters can be coded separately or included in a mode codeword. Which codeword is used for a given mode / sub-mode / parameter combination can affect the coding efficiency gain through intra prediction, and thus the entropy coding technique used to convert the codeword into a bitstream can also have an impact on it.

[0010] Certain intra prediction modes were introduced with H.264, improved in H.265, and further improved in newer coding techniques (e.g., Joint Exploration Model (JEM), Versatile Video Coding (VVC), and Benchmark Set (BMS)). Adjacent sample values belonging to available existing samples can be used to form a predictor block. The sample values of adjacent samples are copied into the predictor block according to a direction. The reference to the direction used can be coded in the bitstream or can be predicted itself.

[0011] Refer to Figure 1A, a subset of 9 predictor directions known from 33 possible predictor directions of H.265 (corresponding to 33 angular modes of 35 intra modes) is depicted in the lower right. The point (101) where the arrows converge indicates the sample being predicted. The arrows indicate the direction of the sample being predicted. For example, arrow (102) indicates that sample (101) is predicted from one or more samples in the upper right at a 45-degree angle to the horizontal direction. Similarly, arrow (103) indicates that sample (101) is predicted from one or more samples in the lower left of sample (101) at a 22.5-degree angle to the horizontal direction.

[0012] Still referring to Figure 1A , a square block (104) of 4×4 samples (represented by the bold dashed line) is depicted in the upper left. Square block (104) includes 16 samples. Each sample is labeled with "S" and its position in the Y dimension (e.g., row index) and its position in the X dimension (e.g., column index). For example, sample S21 is the second sample in the Y dimension (starting from the top) and the first sample in the X dimension (starting from the left). Similarly, sample S44 is the fourth sample in both the Y dimension and the X dimension within block (104). Since the size of the block is 4×4 samples, S44 is located in the lower right. Figure 1A Reference samples following a similar numbering scheme are also shown. The reference samples are labeled with "R" and their Y position (e.g., row index) and X position (column index) relative to block (104). In H.264 and H.265, the predicted sample is adjacent to the block being reconstructed; thus, negative values are not needed.

[0013] Intra picture prediction can work by copying the reference sample values from adjacent samples applicable to the signal-notified prediction direction. For example, assume that the encoded video bitstream includes signaling that, for this block, indicates a prediction direction consistent with arrow (102), that is, predicting the sample from one or more predicted samples in the upper right at a 45-degree angle to the horizontal direction. In this case, samples S41, S32, S23, and S14 are predicted from the same reference sample R05. Then, sample S44 is predicted according to reference sample R08.

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

[0015] With the development of video coding technology, the number of possible directions has increased. In H.264 (in 2003), 9 different directions could be represented. This increased to 33 directions in H.265 (in 2013), and in the present disclosure, up to 65 directions are supported in JEM / VVC / BMS. Experiments have been conducted to identify the most likely directions and to use certain techniques in entropy coding to represent those likely directions with a small number of bits, accepting a certain cost for the less likely directions. Additionally, sometimes the direction itself can be predicted based on the neighboring directions used in the already decoded neighboring blocks.

[0016] Figure 1B A schematic diagram (105) depicting 65 intra prediction directions according to JEM is shown to illustrate the increase in the number of prediction directions over time.

[0017] The mapping of the intra prediction direction bits representing the direction in the encoded video bitstream can vary depending on the video coding technology; and the range can be, for example, from a simple direct mapping of the prediction direction to the intra prediction mode, to codewords, to complex adaptive schemes involving the most likely modes, and similar techniques. However, in all cases, there may be certain directions that are statistically less likely to occur in the video content compared to some other directions. Since the goal of video compression is to reduce redundancy, in a well - functioning video coding technology, those less likely directions will be represented by a larger number of bits compared to the likely directions.

[0018] Motion compensation can be a lossy compression technique and can involve techniques where a block of sample data from a previously reconstructed picture or a portion thereof (reference picture) is spatially offset along the direction indicated by a motion vector (hereinafter referred to as MV) and is used to predict a newly reconstructed picture or picture portion. In some cases, the reference picture can be the same as the picture currently being reconstructed. The MV can have two dimensions, X and Y, or three dimensions, with the third dimension indicating the reference picture being used (the latter can indirectly be the temporal dimension).

[0019] In some video compression techniques, a motion vector (MV) applicable to a certain region of sample data can be predicted based on other MVs, for example, an MV related to another region of sample data that is spatially adjacent to the region being reconstructed and whose decoding order is prior to that of the MV. Doing so can greatly reduce the amount of data required to encode the MV, thereby eliminating redundancy and increasing the compression ratio. MV prediction can work effectively. For example, when encoding an input video signal obtained from a camera (referred to as natural video), there is the following statistical possibility: a region larger than the region applicable to a single MV moves in a similar direction. Therefore, in some cases, a similar motion vector derived from the MVs of adjacent regions can be used to predict the larger region. This makes the MV found for a given region similar to or the same as the MV predicted based on surrounding MVs. Subsequently, after entropy coding, the MV found for the given region can be represented using fewer bits than the number of bits used when directly encoding the MV. In some cases, MV prediction can be an example of lossless compression of a signal (i.e., the MV) derived from the original signal (i.e., the sample stream). In other cases, MV prediction itself can be lossy, for example, due to rounding errors that occur when calculating the predicted value based on multiple surrounding MVs.

[0020] Various MV prediction mechanisms are described in H.265 / HEVC (ITU-T Recommendation H.265, "High Efficiency Video Coding", December 2016). In addition to the multiple MV prediction mechanisms provided by H.265, this application describes a technique hereinafter referred to as "spatial merge".

[0021] Referring to Figure 1C , the current block (111) can include samples that have been discovered by the encoder during the motion search process and are predictable based on a previous block of the same size that has been spatially shifted. Instead of directly encoding the MV, an MV associated with any one of five surrounding samples (labeled A0, A1, and B0, B1, B2 (112 to 116 respectively)) can be used, and the MV is derived from the metadata associated with one or more reference pictures (e.g., the most recent (in decoding order) reference picture). In H.265, MV prediction can use the predictor of the same reference picture that adjacent blocks are using. Summary of the Invention

[0022] Aspects of the present disclosure provide methods and apparatuses for video coding. In some examples, an apparatus for video coding includes a receiving circuit and a processing circuit.

[0023] The processing circuit is configured to obtain prediction information of a current block in a current picture of a video sequence, the prediction information indicating a first prediction mode for the current block. The processing circuit determines whether an adjacent block adjacent to the current block and encoded before the current block uses the first prediction mode. Then, in response to determining that the adjacent block uses the first prediction mode, the processing circuit inserts the prediction information from the adjacent block into a prediction list for the first prediction mode. Finally, the processing circuit encodes the current block according to the prediction list for the first prediction mode.

[0024] According to an aspect of the present invention, in response to determining that the adjacent block uses a second prediction mode different from the first prediction mode, the processing circuit is further configured to determine whether the second prediction mode is an intra prediction mode. Then, in response to determining that the second prediction mode is not an intra prediction mode, the processing circuit inserts the prediction information from the adjacent block into a prediction list for the first prediction mode.

[0025] In one embodiment, the processing circuit determines whether the adjacent block is in the same slice as the current block. A slice is a group of blocks in raster scan order and the blocks in a slice use the same prediction mode. In response to determining that the adjacent block is in the same slice as the current block, the processing circuit inserts the prediction information from the adjacent block into a prediction list for the first prediction mode.

[0026] In one embodiment, the processing circuit determines whether the adjacent block is in the same tile or the same tile group as the current block. A tile is a region of a picture and is processed independently in parallel. A tile group is a group of tiles and the same header is shared among a group of tiles. In response to determining that the adjacent block is in the same tile or the same tile group as the current block, the processing circuit inserts the prediction information from the adjacent block into a prediction list for the first prediction mode.

[0027] In one embodiment, the processing circuit determines whether the adjacent block overlaps with the current block. In response to determining that the adjacent block does not overlap with the current block, the processing circuit inserts the prediction information from the adjacent block into a prediction list for the first prediction mode.

[0028] In one embodiment, the first prediction mode includes at least one of an intra block copy prediction mode and an inter prediction mode.

[0029] In one embodiment, the prediction information from the adjacent block includes at least one of a block vector and a motion vector. The block vector indicates an offset between the adjacent block and the current block and is used to predict the current block when encoding the adjacent block in an intra block copy prediction mode. The motion vector is used to predict the current block when encoding the adjacent block in an inter prediction mode.

[0030] Aspects of the present invention also provide a non-transitory computer-readable medium storing instructions that, when executed by a computer for video encoding, cause the computer to perform a method of video encoding. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Other features, properties, and various advantages of the disclosed subject matter will become more apparent from the following detailed description and the accompanying drawings, in which:

[0032] Figure 1A is a schematic diagram of an exemplary subset of intra prediction modes;

[0033] Figure 1B is an illustration of exemplary intra prediction directions;

[0034] Figure 1C is a schematic diagram of spatial merge candidates for a current block and its surroundings in one example;

[0035] Figure 2 is a schematic diagram of a simplified block diagram of a communication system according to one embodiment;

[0036] Figure 3 is a schematic diagram of a simplified block diagram of a communication system according to one embodiment;

[0037] Figure 4 is a schematic diagram of a simplified block diagram of a decoder according to one embodiment;

[0038] Figure 5 is a schematic diagram of a simplified block diagram of an encoder according to one embodiment;

[0039] Figure 6 shows a block diagram of an encoder according to another embodiment;

[0040] Figure 7 shows a block diagram of a decoder according to another embodiment;

[0041] Figure 8 shows an example diagram of an intra block copy prediction mode according to one embodiment;

[0042] Figures 9A to 9D shows an exemplary update process within the valid search range of the intra block copy prediction mode according to one embodiment;

[0043] Figure 10 shows a flowchart outlining an exemplary process according to an embodiment of the present disclosure;

[0044] Figure 11 is a schematic diagram of a computer system according to one embodiment. DETAILED DESCRIPTION

[0045] Figure 2 FIG. 1 shows a simplified block diagram of a communication system (200) according to an embodiment of the present disclosure. The communication system (200) includes a plurality of terminal devices that can communicate with each other through, for example, a network (250). For example, the communication system (200) includes a first pair of terminal devices (210) and (220) interconnected by a network (250). In Figure 2 the example of, the first pair of terminal devices (210) and (220) perform unidirectional data transmission. For example, the terminal device (210) can encode video data (such as a video picture stream captured by the terminal device (210)) for transmission through the network (250) to another terminal device (220). The encoded video data can be transmitted in the form of one or more encoded video bitstreams. The terminal device (220) can receive the encoded video data from the network (250), decode the encoded video data to recover the video pictures, and display the video pictures based on the recovered video data. Unidirectional data transmission is relatively common in applications such as media services.

[0046] In another example, the communication system (200) includes a second pair of terminal devices (230) and (240) that perform bidirectional transmission of encoded video data, which can occur, for example, during a video conference. For bidirectional data transmission, in one example, each of the terminal devices (230) and (240) can encode video data (such as a video picture stream captured by the terminal device) for transmission through the network (250) to the other of the terminal devices (230) and (240). Each of the terminal devices (230) and (240) can also receive the encoded video data transmitted by the other of the terminal devices (230) and (240), decode the encoded video data to recover the video pictures, and display the video pictures on an accessible display device based on the recovered video data.

[0047] In Figure 2In the example, the terminal devices (210), (220), (230), and (240) may be shown as servers, personal computers, and smart phones, but the principles of the present disclosure are not limited thereto. Embodiments of the present disclosure are applicable to laptop computers, tablet computers, media players, and / or dedicated video conferencing devices. The network (250) represents any number of networks that transfer encoded video data between the terminal devices (210), (220), (230), and (240), including, for example, wired (wired) and / or wireless communication networks. The communication network (250) may exchange data in circuit-switched and / or packet-switched channels. Representative networks include telecommunications networks, local area networks, wide area networks, and / or the Internet. For the purposes of this discussion, unless otherwise explained below, the architecture and topology of the network (250) may be immaterial to the operation of the present disclosure.

[0048] As an example of the application of the disclosed subject matter, Figure 3 shows the placement of a video encoder and a video decoder in a streaming environment. The disclosed subject matter is equally applicable to other video-enabled applications, including, for example, video conferencing, digital TV, storing compressed video on digital media including CDs, DVDs, memory sticks, etc.

[0049] A streaming system may include an acquisition subsystem (313), which may include a video source (301), such as a digital camera, that creates, for example, an uncompressed video picture stream (302). In the example, the video picture stream (302) includes samples taken by the digital camera. Compared to the encoded video data (304) (or encoded video bitstream), the video picture stream (302), depicted as a thick line to emphasize the high data volume, may be processed by an electronic device (320) that includes a video encoder (303) coupled to the video source (301). The video encoder (303) may include hardware, software, or a combination of both to implement or carry out aspects of the disclosed subject matter described in more detail below. Compared to the video picture stream (302), the encoded video data (304) (or encoded video bitstream (304)), depicted as a thin line to emphasize the lower data volume, may be stored on a streaming server (305) for future use. One or more streaming client subsystems, such as Figure 3The client subsystems (306) and client subsystems (308) therein can access the streaming server (305) to retrieve copies (307) and copies (309) of the encoded video data (304). The client subsystem (306) can include, for example, a video decoder (310) in an electronic device (330). The video decoder (310) decodes the incoming copy (307) of the encoded video data and generates an output video picture stream (311) that can be presented on a display (312) (such as a display screen) or another presentation device (not depicted). In some streaming systems, the encoded video data (304), the encoded video data (307), and the encoded video data (309) (such as a video bitstream) can be encoded according to certain video coding / compression standards. Examples of such standards include ITU-T Recommendation H.265. In an example, a video coding standard that is being developed is informally referred to as Versatile Video Coding (VVC), and the disclosed subject matter can be used in the context of VVC.

[0050] It should be noted that the electronic device (320) and the electronic device (330) can include other components (not shown). For example, the electronic device (320) can include a video decoder (not shown), and the electronic device (330) can also include a video encoder (not shown).

[0051] Figure 4 A block diagram of a video decoder (410) according to an embodiment of the present disclosure is shown. The video decoder (410) can be included in an electronic device (430). The electronic device (430) can include a receiver (431) (such as a receiving circuit). The video decoder (410) can be used to replace Figure 3 the video decoder (310) in the example.

[0052] A receiver (431) may receive one or more encoded video sequences to be decoded by a video decoder (410); in the same or another embodiment, one encoded video sequence is received at a time, where 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 (401), which may be a hardware / software link to a storage device storing the encoded video data. The receiver (431) may receive the encoded video data and other data, such as encoded audio data and / or auxiliary data streams, that may be forwarded to their respective consuming entities (not depicted). The receiver (431) may separate the encoded video sequences from the other data. To prevent network jitter, a buffer memory (415) may be coupled between the receiver (431) and an entropy decoder / parser (420) (hereinafter referred to as "parser (420)"). In some applications, the buffer memory (415) is part of the video decoder (410). In other cases, the buffer memory (415) may be provided external to the video decoder (410) (not depicted). In yet other cases, a buffer memory (not depicted) may be provided external to the video decoder (410) to, for example, prevent network jitter, and another buffer memory (415) may be configured inside the video decoder (410) to, for example, handle presentation timing. When the receiver (431) receives data from a storage / forward device with sufficient bandwidth and controllability or from an isochronous network, the buffer memory (415) may not be needed or may be made smaller. For use on a service packet network such as the Internet, a buffer memory (415) may be needed, which may be relatively large and may advantageously have an adaptive size and may be implemented at least partially in an operating system or a similar element (not depicted) external to the video decoder (410).

[0053] The video decoder (410) may include a parser (420) to reconstruct symbols (421) from the encoded video sequences. The categories of these symbols include information for managing the operation of the video decoder (410) and potential information for controlling a display device (412) such as a display screen, which is not an integral part of the electronic device (430) but may be coupled to the electronic device (430), such as Figure 4As shown. The control information for the display device may be in the form of a Supplemental Enhancement Information (SEI message) or a parameter set segment (not depicted) of Video Usability Information (VUI). The parser (420) may perform parsing / entropy decoding on the received encoded video sequence. The encoding of the encoded video sequence may be performed according to a video coding technology or standard and may follow various principles, including variable length coding, Huffman coding, arithmetic coding with or without context sensitivity, and so on. The parser (420) may extract subgroup parameter sets for at least one subgroup of pixels in the video decoder from the encoded video sequence based on at least one parameter corresponding to the group. The subgroups may include Group of Pictures (GOP), pictures, tiles, slices, macroblocks, Coding Units (CUs), blocks, Transform Units (TUs), Prediction Units (PUs), and so on. The parser (420) may also extract information from the encoded video sequence, such as transform coefficients, quantizer parameter values, motion vectors, and so on.

[0054] The parser (420) may perform an entropy decoding / parsing operation on the video sequence received from the buffer memory (415) to create symbols (421).

[0055] Depending on the type of the encoded video picture or a part of the encoded video picture (e.g., inter-picture and intra-picture, inter-block and intra-block) and other factors, the reconstruction of the symbols (421) may involve multiple different units. Which units are involved and the way they are involved may be controlled by the subgroup control information parsed by the parser (420) from the encoded video sequence. For the sake of brevity, such subgroup control information flows between the parser (420) and the multiple units below are not depicted.

[0056] In addition to the functional blocks already mentioned, the video decoder (410) may be conceptually divided into several functional units as described below. In a practical implementation operating under commercial constraints, many of these units interact closely with each other and may be at least partially integrated with each other. However, for the purpose of describing the disclosed subject matter, it is appropriate to conceptually divide into the functional units below.

[0057] The first unit is a scaler / inverse transform unit (451). The scaler / inverse transform unit (451) receives the quantized transform coefficients as symbols (421) and control information from the parser (420), including which transform mode to use, block size, quantization factor, quantization scaling matrix, etc. The scaler / inverse transform unit (451) can output a block including sample values, and the sample values can be input into an aggregator (455).

[0058] In some cases, the output samples of the scaler / inverse transform unit (451) can belong to intra-coded blocks; that is: blocks that do not use predictive information from a previously reconstructed picture, but can use predictive information from a previously reconstructed part of the current picture. Such predictive information can be provided by an intra-picture prediction unit (452). In some cases, the intra-picture prediction unit (452) generates a block with the same size and shape as the block being reconstructed using the surrounding reconstructed information extracted from the current picture buffer (458). For example, the current picture buffer (458) buffers a partially reconstructed current picture and / or a fully reconstructed current picture. In some cases, based on each sample, the aggregator (455) adds the prediction information generated by the intra-prediction unit (452) to the output sample information provided by the scaler / inverse transform unit (451).

[0059] In other cases, the output samples of the scaler / inverse transform unit (451) can belong to inter-coded and potentially motion-compensated blocks. In this case, the motion compensation prediction unit (453) can access the reference picture memory (457) to extract samples for prediction. After motion-compensating the extracted samples according to the symbols (421) belonging to the block, these samples can be added by the aggregator (455) to the output of the scaler / inverse transform unit (451) (which is called the residual sample or residual signal in this case), thereby generating output sample information. The motion compensation prediction unit (453) obtaining the prediction samples from an address within the reference picture memory (457) can be controlled by a motion vector, and the motion vector is in the form of a symbol (421) for use by the motion compensation prediction unit (453), and the symbol (421) can have, for example, X, Y, and reference picture components. Motion compensation can also include interpolation of the sample values extracted from the reference picture memory (457), a motion vector prediction mechanism, etc. when using sub-sample accurate motion vectors.

[0060] The output samples of the aggregator (455) may undergo various loop filtering techniques in the loop filter unit (456). Video compression techniques may include in-loop filter techniques that are controlled by parameters included in the encoded video sequence (also referred to as the encoded video bitstream) and that are available as symbols (421) from the parser (420) to the loop filter unit (456). However, video compression techniques may also respond to meta-information obtained during the decoding of previous (in decoding order) parts of the encoded picture or the encoded video sequence, and to previously reconstructed and loop-filtered sample values.

[0061] The output of the loop filter unit (456) may be a sample stream that may be output to the display device (412) and stored in the reference picture memory (457) for subsequent inter-picture prediction.

[0062] Once fully reconstructed, some encoded pictures may be used as reference pictures for future prediction. For example, once the encoded picture corresponding to the current picture has been fully reconstructed and the encoded picture has been identified (by, for example, the parser (420)) as a reference picture, the current picture buffer (458) may become part of the reference picture memory (457), and a new current picture buffer may be reallocated before starting the reconstruction of subsequent encoded pictures.

[0063] The video decoder (410) may perform decoding operations according to, for example, a predetermined video compression technique in the ITU-T H.265 standard. The encoded video sequence may conform to the syntax specified by the video compression technique or standard in the sense that the encoded video sequence follows the syntax of the video compression technique or standard and the profile recorded in the video compression technique or standard. Specifically, the profile may select some tools from all the tools available in the video compression technique or standard as the only tools available under that profile. For compliance, it may also be required that the complexity of the encoded video sequence be within the range defined by the level of the video compression technique or standard. In some cases, the level limits the maximum picture size, the maximum frame rate, the maximum reconstruction sampling rate (measured, for example, in megasamples per second), the maximum reference picture size, etc. In some cases, the limits set by the level may be further limited by the Hypothetical Reference Decoder (HRD) specification and the metadata for HRD buffer management signaled in the encoded video sequence.

[0064] In one embodiment, the receiver (431) may receive additional (redundant) data along with the encoded video. This additional data may be included as part of the encoded video sequence. The additional data may be used by the video decoder (410) to decode the data appropriately and / or reconstruct the original video data more accurately. The additional data may be in the form of, for example, temporal, spatial, or signal noise ratio (SNR) enhancement layers, redundant slices, redundant pictures, forward error correction codes, etc.

[0065] Figure 5 A block diagram of a video encoder (503) according to an embodiment of the present disclosure is shown. The video encoder (503) is included in an electronic device (520). The electronic device (520) includes a transmitter (540) (e.g., transmission circuitry). The video encoder (503) may be used in place of Figure 3 the video encoder (303) in the example.

[0066] The video encoder (503) may receive video samples from a video source (501) (which is not Figure 5 part of the electronic device (520) in the example), and the video source may capture video images to be encoded by the video encoder (503). In another example, the video source (501) is part of the electronic device (520).

[0067] The video source (501) may provide a source video sequence in the form of a digital video sample stream to be encoded by the video encoder (503), and the digital video sample stream may have any suitable bit depth (e.g., 8-bit, 10-bit, 12-bit,...), any color space (e.g., BT.601 Y CrCB, RGB,...), and any suitable sampling structure (e.g., Y CrCb 4:2:0, Y CrCb 4:4:4). In a media service system, the video source (501) may be a storage device storing previously prepared video. In a video conferencing system, the video source (501) may be a camera that captures local image information as a video sequence. The video data may be provided as a plurality of individual pictures, which are given motion when viewed in sequence. The pictures themselves may be constructed as spatial pixel arrays, where each pixel may include one or more samples depending on the sampling structure, color space, etc. used. Those skilled in the art can easily understand the relationship between pixels and samples. The following focuses on describing samples.

[0068] According to an embodiment, a video encoder (503) may encode and compress pictures of a source video sequence into an encoded video sequence (543) in real time or under any other time constraints required by an application. Enforcing an appropriate encoding speed is a function of a controller (550). In some embodiments, the controller (550) controls and is functionally coupled to other functional units as described below. For the sake of brevity, the couplings are not depicted in the figures. Parameters set by the controller (550) may include rate control related parameters (picture skipping, quantizer, λ value of rate-distortion optimization techniques...), picture size, group of pictures (GOP) layout, maximum motion vector search range, etc. The controller (550) may be configured to have other suitable functions that relate to optimizing the video encoder (503) for a certain system design.

[0069] In some embodiments, the video encoder (503) is configured to operate in an encoding loop. As a simple description, in an example, the encoding loop may include a source encoder (530) (e.g., responsible for creating symbols, such as a symbol stream, based on an input picture to be encoded and reference pictures) and a (local) decoder (533) embedded in the video encoder (503). The decoder (533) reconstructs the symbols to create sample data in a manner similar to how a (remote) decoder creates sample data (since in the video compression techniques contemplated by the disclosed subject matter, any compression between the symbols and the encoded video bitstream is lossless). The reconstructed sample stream (sample data) is input into a reference picture memory (534). Since the decoding of the symbol stream produces a bit-exact result independent of the decoder location (local or remote), the content in the reference picture memory (534) is also bit-exact corresponding between the local encoder and the remote encoder. In other words, the reference picture samples "seen" by the prediction part of the encoder are exactly the same as the sample values that the decoder will "see" when using prediction during decoding. This reference picture synchronization principle (and the drift that occurs, for example, when synchronization cannot be maintained due to channel errors) is also used in some related techniques.

[0070] The operation of the "local" decoder (533) may be the same as that of the "remote" decoder of the video decoder (410) described in detail above in conjunction with Figure 4 However, briefly referring additionally to Figure 4 , when symbols are available and the entropy encoder (545) and parser (420) can encode / decode the symbols losslessly into the encoded video sequence, the entropy decoding part of the video decoder (410), including the buffer memory (415) and the parser (420), may not be fully implementable in the local decoder (533).

[0071] At this point, it can be observed that any decoder technique other than parsing / entropy decoding that exists in the decoder must also exist in the corresponding encoder in a substantially identical functional form. For this reason, the disclosed subject matter focuses on decoder operations. The description of encoder techniques can be simplified because encoder techniques are inverse to the decoder techniques described comprehensively. A more detailed description is needed only in certain areas and is provided below.

[0072] During operation, in some examples, the source encoder (530) may perform motion compensated predictive coding. Referring to one or more previously encoded pictures designated as "reference pictures" in the video sequence, this motion compensated predictive coding performs predictive coding on the input picture. In this way, the coding engine (532) encodes the difference between the pixel blocks of the input picture and the pixel blocks of the reference picture, which can be selected as the prediction reference for the input picture.

[0073] The local video decoder (533) may decode the encoded video data of a picture that can be designated as a reference picture based on the symbols created by the source encoder (530). The operation of the coding engine (532) can advantageously be a lossy process. When the encoded video data can be decoded at a video decoder ( Figure 5 not shown), the reconstructed video sequence can generally be a copy of the source video sequence with some errors. The local video decoder (533) replicates the decoding process that can be performed by the video decoder on the reference picture and can store the reconstructed reference picture in the reference picture cache (534). In this way, the video encoder (503) can locally store a copy of the reconstructed reference picture that has the same content (in the absence of transmission errors) as the reconstructed reference picture to be obtained by the remote video decoder.

[0074] The predictor (535) may perform a prediction search for the coding engine (532). That is, for a new picture to be encoded, the predictor (535) may search the reference picture memory (534) for sample data (as candidate reference pixel blocks) or some metadata, such as reference picture motion vectors, block shapes, etc., that can be used as an appropriate prediction reference for the new picture. The predictor (535) may operate on a per pixel block basis of the sample blocks to find a suitable prediction reference. In some cases, as determined by the search results obtained by the predictor (535), the input picture may have prediction references taken from multiple reference pictures stored in the reference picture memory (534).

[0075] The controller (550) may manage the encoding operations of the source encoder (530), including, for example, setting parameters and subgroup parameters for encoding the video data.

[0076] The outputs of all the above functional units can be entropy-coded in an entropy encoder (545). The entropy encoder (545) performs lossless compression on the symbols generated by the various functional units according to techniques such as Huffman coding, variable length coding, arithmetic coding, etc., thereby transforming the symbols into an encoded video sequence.

[0077] The transmitter (540) can buffer the encoded video sequence created by the entropy encoder (545) to prepare for transmission over a communication channel (560), which can be a hardware / software link to a storage device that will store the encoded video data. The transmitter (540) can combine the encoded video data from the video encoder (503) with other data to be transmitted, such as encoded audio data and / or auxiliary data streams (source not shown).

[0078] The controller (550) can manage the operation of the video encoder (503). During encoding, the controller (550) can assign a certain encoded picture type to each encoded picture, but this may affect the encoding techniques applicable to the corresponding picture. For example, pictures can typically be assigned to any of the following picture types:

[0079] An intra picture (I picture), which can be a picture that can be encoded and decoded without using any other picture in the sequence as a prediction source. Some video codecs allow different types of intra pictures, including, for example, Independent Decoder Refresh (IDR) pictures. Those skilled in the art are aware of the variants of I pictures and their corresponding applications and characteristics.

[0080] A predictive picture (P picture), which can be a picture that can be encoded and decoded using intra prediction or inter prediction, where the intra prediction or inter prediction uses at most one motion vector and a reference index to predict the sample values of each block.

[0081] A bi-predictive picture (B picture), which can be a picture that can be encoded and decoded using intra prediction or inter prediction, where the intra prediction or inter prediction uses at most two motion vectors and reference indices to predict the sample values of each block. Similarly, multiple predictive pictures can use more than two reference pictures and associated metadata for reconstructing a single block.

[0082] Source pictures can typically be spatially subdivided into multiple sample blocks (e.g., blocks of 4×4, 8×8, 4×8, or 16×16 samples), and encoded block by block. These blocks can be prediction-encoded with reference to other (already encoded) blocks, which are determined by the coding assignment applied to the corresponding picture of the block. For example, blocks of an I picture can be non-prediction-encoded, or the block can be prediction-encoded with reference to already encoded blocks of the same picture (spatial prediction or intra prediction). Pixel blocks of a P picture can be prediction-encoded with reference to a previously encoded reference picture by spatial prediction or by temporal prediction. Blocks of a B picture can be prediction-encoded with reference to one or two previously encoded reference pictures by spatial prediction or by temporal prediction.

[0083] The video encoder (503) can perform encoding operations according to a predetermined video coding technique or standard such as the ITU-T H.265 recommendation. In operation, the video encoder (503) can perform various compression operations, including prediction coding operations that utilize the temporal and spatial redundancies in the input video sequence. Thus, the encoded video data can conform to the syntax specified by the video coding technique or standard being used.

[0084] In one embodiment, the transmitter (540) can transmit additional data when transmitting the encoded video. The source encoder (530) can include such data as part of the encoded video sequence. The additional data can include other forms of redundant data such as temporal / spatial / SNR enhancement layers, redundant pictures and slices, SEI messages, VUI parameter set fragments, etc.

[0085] The captured video can be a plurality of source pictures (video pictures) in a time series. Intra picture prediction (often simplified to intra prediction) utilizes the spatial correlation within a given picture, while inter picture prediction utilizes the (temporal or other) correlation between pictures. In an example, the particular picture being encoded / decoded is segmented into blocks, and the particular picture being encoded / decoded is referred to as the current picture. When a block in the current picture is similar to a reference block in a reference picture that has been previously encoded and is still buffered in the video, the block in the current picture can be encoded by a vector called a motion vector. The motion vector points to the reference block in the reference picture, and in the case of using multiple reference pictures, the motion vector can have a third dimension that identifies the reference picture.

[0086] In some embodiments, bidirectional prediction techniques can be used for 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 past and future respectively in display order). A block in the current picture can 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 can be predicted by a combination of the first reference block and the second reference block.

[0087] In addition, the merge mode technique can be used for inter - picture prediction to improve the coding efficiency.

[0088] According to some embodiments of the present disclosure, predictions such as inter - picture prediction and intra - picture prediction are performed on a block - by - block basis. For example, according to the HEVC standard, a picture in a video picture sequence is segmented into coding tree units (CTUs) for compression, and the CTUs in a picture have the same size, such as 64×64 pixels, 32×32 pixels, or 16×16 pixels. Generally, a CTU includes three coding tree blocks (CTBs), which are one 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 an example, each CU is analyzed to determine the prediction type for the CU, such as an inter - prediction type or an intra - prediction type. Depending on the temporal and / or spatial predictability, the CU is split into one or more prediction units (PUs). Generally, each PU includes a luminance prediction block (PB) and two chrominance PBs. In one embodiment, the prediction operation in encoding (encoding / decoding) is performed on a prediction - block basis. Taking the luminance prediction block as an example of a prediction block, the prediction block includes a matrix of values (e.g., luminance values) for pixels, such as 8×8 pixels, 16×16 pixels, 8×16 pixels, 16×8 pixels, etc.

[0089] Figure 6 A diagram of a video encoder (603) according to another embodiment of the present disclosure is shown. The video encoder (603) is configured to receive a processing block (e.g., a prediction block) of sample values within a current video picture in a video picture sequence and encode the processing block into an encoded picture that is part of an encoded video sequence. In an example, the video encoder (603) is used instead of Figure 3 the video encoder (303) in the example.

[0090] In the HEVC example, the video encoder (603) receives a matrix of sample values for processing a block, such as a prediction block of 8×8 samples. The video encoder (603) uses, for example, rate-distortion (RD) optimization to determine whether to use an intra mode, an inter mode, or a bi-prediction mode to best encode the processing block. When encoding the processing block in the intra mode, the video encoder (603) may use intra prediction techniques to encode the processing block into an encoded picture; and when encoding the processing block in the inter mode or the bi-prediction mode, the video encoder (603) may use inter prediction or bi-prediction techniques, respectively, to encode the processing block into an encoded picture. In some video coding techniques, the merge mode may be an inter-picture prediction sub-mode, in which a motion vector is derived from one or more motion vector predictors without resorting to encoded motion vector components external to the predictor. In some other video coding techniques, there may be motion vector components applicable to the subject block. In the example, the video encoder (603) includes other components, such as a mode decision module (not shown) for determining the mode of the processing block.

[0091] In Figure 6 the example of Figure 6 shown, the video encoder (603) includes an inter encoder (630), an intra encoder (622), a residual calculator (623), a switch (626), a residual encoder (624), a general controller (621), and an entropy encoder (625) coupled together as

[0092] The inter encoder (630) is configured to receive samples of a current block (e.g., the processing block), compare the block with one or more reference blocks in a reference picture (e.g., blocks in a previous picture and a later picture), generate inter prediction information (e.g., redundancy information description, motion vector, merge mode information according to inter coding techniques), and calculate an inter prediction result (e.g., a predicted block) based on the inter prediction information using any suitable technique. In some examples, the reference picture is a decoded reference picture decoded based on the encoded video information.

[0093] The intra encoder (622) is configured to receive samples of a current block (e.g., the processing block), compare the block with encoded blocks in the same picture in some cases, generate quantization coefficients after transformation, and also generate intra prediction information in some cases (e.g., according to intra prediction direction information of one or more intra coding techniques). In the example, the intra encoder (622) also calculates an intra prediction result (e.g., a predicted block) based on the intra prediction information and a reference block in the same picture.

[0094] The general controller (621) is configured to determine general control data and control other components of the video encoder (603) based on the general control data. In an example, the general controller (621) determines the mode of a block and provides a control signal to the switch (626) based on the mode. For example, when the mode is an intra mode, the general controller (621) controls the switch (626) to select the intra mode result for use by the residual calculator (623) and controls the entropy encoder (625) to select the intra prediction information and add the intra prediction information in the bitstream; and when the mode is an inter mode, the general controller (621) controls the switch (626) to select the inter prediction result for use by the residual calculator (623) and controls the entropy encoder (625) to select the inter prediction information and add the inter prediction information in the bitstream.

[0095] The residual calculator (623) is configured to calculate the difference (residual data) between the received block and a prediction result selected from the intra encoder (622) or the inter encoder (630). The residual encoder (624) is configured to operate based on the residual data to encode the residual data to generate transform coefficients. In an example, the residual encoder (624) is configured to transform the residual data from the spatial domain to the frequency domain and generate transform coefficients. The transform coefficients are then subjected to a quantization process to obtain quantized transform coefficients. In various embodiments, the video encoder (603) further includes a residual decoder (628). The residual decoder (628) is configured to perform an inverse transform and generate decoded residual data. The decoded residual data can be appropriately used by the intra encoder (622) and the inter encoder (630). For example, the inter encoder (630) can generate a decoded block based on the decoded residual data and the inter prediction information, and the intra encoder (622) can generate a decoded block based on the decoded residual data and the intra prediction information. The decoded block is appropriately processed to generate a decoded picture, and in some examples, the decoded picture can be buffered in a memory circuit (not shown) and used as a reference picture.

[0096] The entropy encoder (625) is configured to format the bitstream to produce an encoded block. The entropy encoder (625) is configured to generate various information according to a suitable standard such as the HEVC standard. In an example, the entropy encoder (625) is configured to include the general control data, the selected prediction information (e.g., intra prediction information or inter prediction information), the residual information, and other suitable information in the bitstream. It should be noted that according to the disclosed subject matter, when encoding a block in the merge submode of the inter mode or the bi-prediction mode, there is no residual information.

[0097] Figure 7FIG. showing a video decoder (710) according to another embodiment of the present disclosure. The video decoder (710) 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 (710) is used to replace Figure 3 the video decoder (310) in the example.

[0098] In Figure 7 the example, the video decoder (710) includes an entropy decoder (771), an inter-frame decoder (780), a residual decoder (773), a reconstruction module (774), and an intra-frame decoder (772) coupled together as Figure 7 shown.

[0099] The entropy decoder (771) may be configured to reconstruct certain symbols based on the encoded picture, where these symbols represent the syntax elements that make up the encoded picture. Such symbols may include, for example, the mode used to encode the block (e.g., intra-mode, inter-mode, bi-prediction mode, a merge sub-mode of the latter two, or another sub-mode), prediction information that can identify certain samples or metadata for use by the intra-frame decoder (772) or the inter-frame decoder (780) for prediction (e.g., intra-prediction information or inter-prediction information), residual information in the form of, for example, quantized transform coefficients, and so on. In an example, when the prediction mode is an inter or bi-prediction mode, the inter-prediction information is provided to the inter-frame decoder (780); and when the prediction type is an intra-prediction type, the intra-prediction information is provided to the intra-frame decoder (772). The residual information may be inverse quantized and provided to the residual decoder (773).

[0100] The inter-frame decoder (780) is configured to receive the inter-frame prediction information and generate an inter-frame prediction result based on the inter-frame prediction information.

[0101] The intra-frame decoder (772) is configured to receive the intra-frame prediction information and generate a prediction result based on the intra-frame prediction information.

[0102] The residual decoder (773) is configured to perform inverse quantization to extract the dequantized transform coefficients and process the dequantized transform coefficients to transform the residual from the frequency domain to the spatial domain. The residual decoder (773) may also require certain control information (used to include quantization parameter (QP)), and this information may be provided by the entropy decoder (771) (the data path is not depicted as this is merely low-volume control information).

[0103] The reconstruction module (774) is configured to combine, in the spatial domain, the residual output by the residual decoder (773) with the prediction result (which may be output by an inter-frame prediction module or an intra-frame prediction module as the case may be) to form a reconstructed block, which may be part of a reconstructed picture, which in turn may be part of a reconstructed video. It should be noted that other suitable operations, such as de-blocking operations, may be performed to improve the visual quality.

[0104] It should be noted that any suitable technology may be used to implement the video encoders (303), (503), and (603) and the video decoders (310), (410), and (710). In one embodiment, one or more integrated circuits may be used to implement the video encoders (303), (503), and (603) and the video decoders (310), (410), and (710). In another embodiment, one or more processors executing software instructions may be used to implement the video encoders (303), (503), and (503) and the video decoders (310), (410), and (710).

[0105] Generally, block-based compensation is based on different pictures. This block-based compensation may be referred to as motion compensation. However, block compensation may be done based on previously reconstructed regions within the same picture. This block compensation may be referred to as intra-picture block compensation, current picture reference (CPR), or intra-block copy (IBC).

[0106] In the IBC prediction mode, in some embodiments, the displacement vector indicating the offset between the current block and the reference block within the same picture is referred to as a block vector (BV). It is worth noting that the reference block has been reconstructed before the current block. Additionally, for parallel processing, the reference regions at the tile / slice boundary or the wavefront trapezoid boundary may be excluded from being used as available reference blocks. Due to these constraints, the block vector may be different from the motion vector which can take any value (positive or negative in the x or y direction) in motion compensation.

[0107] Figure 8 An embodiment of the intra-block copy prediction mode according to an embodiment of the present invention is shown. In Figure 8 , the grey blocks indicate that these blocks have been decoded, while the white blocks indicate that these blocks have not been decoded or are being decoded. Thus, in the current picture (800), the block vector (802) points from the current block (801) to the reference block (803). The current block (801) is being reconstructed, while the reference block (803) has already been reconstructed.

[0108] According to some embodiments, the encoding of block vectors can be explicit or implicit. In the explicit mode, the difference between the block vector and the predictor of the block vector is signaled. In the implicit mode, the block vector is recovered based on the predictor of the block vector in a manner similar to motion vector prediction in the merge mode. In one embodiment, the resolution of the block vector can be restricted to integer positions, but in another embodiment, the resolution of the block vector can be allowed to point to fractional positions.

[0109] According to some embodiments, a block-level flag (referred to as the IBC flag) or a reference index can be used to signal the use of the IBC prediction mode at the block level. When the reference index method is used, the current decoded picture is considered as a reference picture placed at the last position in the reference picture list. This reference picture can also be managed together with other temporal reference pictures in the decoded picture buffer (DPB).

[0110] In addition, there are some variations for the IBC prediction mode. In some instances, the reference block is flipped horizontally or vertically before being used to predict the current block, which can be referred to as the flipped IBC prediction mode. In other examples, each compensation unit within the M×N encoded block is an M×1 row or a 1×N row, which can be referred to as the row-based IBC prediction mode.

[0111] In the current VVC, the search range of the IBC prediction mode is restricted within the current CTU. In some embodiments, the memory for storing reference samples in the IBC prediction mode is of 1 CTU size (e.g., four 64×64 regions). For example, the memory stores four 64×64 sample regions, where one 64×64 sample region can be the currently reconstructed samples, and the other three 64×64 sample regions can be reference samples.

[0112] In some embodiments, the effective search range of the IBC prediction mode can be extended to a part of the left CTU of the current CTU while keeping the memory unchanged (i.e., 1 CTU size, 4 64×64 regions). For example, an update process can be used in such an effective search range.

[0113] Figures 9A to 9D An embodiment of the update process of the effective search range using the IBC prediction mode (i.e., intra picture block compensation) according to an embodiment of the present disclosure is shown. The update process can be performed based on 64×64 luma samples. For each of the four 64×64 block regions in the memory of CTU size, the reference samples in the same region from the left CTU can be used to predict the encoded blocks in the current CTU until any block in the same region of the current CTU is being encoded or has been encoded.

[0114] During this process, in some embodiments, the stored reference samples from the left CTU are updated with the reconstructed samples from the current CTU. In Figures 9A to 9D , the gray blocks indicate the reconstructed blocks, the white blocks indicate the non-reconstructed blocks, and the blocks with vertical stripes and the text "Curr" indicate the current encoding / decoding blocks. Further, in each figure, the four leftmost blocks (911)-(914) belong to the left CTU (910), and the four rightmost blocks (901)-(904) belong to the current CTU (900).

[0115] Notably, all four blocks (911)-(914) of the left CTU (910) have been reconstructed. Thus, the memory initially stores all four of these blocks of the reference samples from the left CTU (910), and then the blocks of the reference samples from the left CTU (910) are updated with the current blocks from the same regions in the current CTU (900).

[0116] For example, in Figure 9A , the current block (901) in the current CTU (900) is being reconstructed, and the co-locate block in the left CTU (910) of the current block (901) is block (911). The co-locate block (911) is in the same region of the left CTU (910) as the region in the current CTU (900) where the current block (901) is located. Thus, the memory region storing the reference sample of the co-locate block (911) is updated to store the reconstructed sample of the current block (901), and an "X" is marked in the co-locate block (911) in Figure 9A to indicate that the reference sample of the co-locate block (911) is not stored in the memory.

[0117] Similarly, in Figure 9B , the current block (902) in the current CTU (900) is being reconstructed, and the co-locate block in the left CTU (910) of the current block (902) is block (912). The co-locate block (912) is in the same region of the left CTU (910) as the region in the current CTU (900) where the current block (902) is located. Thus, the memory region storing the reference sample of the co-locate block (912) is updated to store the reconstructed sample of the current block (902), and an "X" is marked in the co-locate block (912) in Figure 9B to indicate that the reference sample of the co-locate block (912) is not stored in the memory.

[0118] In Figure 9CAmong them, the current block (903) in the current CTU (900) is being reconstructed, and the co-located block in the left CTU (910) of the current block (903) is block (913). The co-located block (913) is in the same area of the left CTU (910) as the area in the current CTU (900) where the current block (903) is located. Therefore, the memory area storing the reference samples of the co-located block (913) is updated to store the reconstructed samples of the current block (903), and an "X" is marked in the co-located block (913) in Figure 9C to indicate that the reference samples of the co-located block (913) are not stored in the memory.

[0119] In Figure 9D Among them, the current block (904) in the current CTU (900) is being reconstructed, and the co-located block in the left CTU (910) of the current block (904) is block (914). The co-located block (914) is in the same area of the left CTU (910) as the area in the current CTU (900) where the current block (904) is located. Therefore, the memory area storing the reference samples of the co-located block (914) is updated to store the reconstructed samples of the current block (904), and an "X" is marked in the co-located block (914) in Figure 9C to indicate that the reference samples of the co-located block (914) are not stored in the memory.

[0120] According to some embodiments, in the intra prediction mode, if there are adjacent blocks and the adjacent blocks have been reconstructed before the current coding block, the adjacent blocks can be used as predictors for the current coding block. In some embodiments, in the inter prediction mode, in addition to there being adjacent blocks and the adjacent blocks having been reconstructed before the current coding block, if the adjacent blocks are not encoded in the intra prediction mode, the adjacent blocks can be used as predictors for the current coding block.

[0121] However, when it comes to the intra block copy prediction mode and it is regarded as a separate mode different from the intra prediction mode or the inter prediction mode, the availability of adjacent blocks becomes more complicated. Therefore, it is necessary to develop a suitable method for checking the availability of adjacent blocks. In this regard, embodiments of the present disclosure propose a method for effectively checking the availability of adjacent blocks of the current coding block.

[0122] When the block vector prediction list (in the merge list or with block vector differential coding) and the motion vector prediction list (in the merge list or with motion vector differential coding) in the IBC prediction mode are constructed separately, some embodiments use unified adjacent availability check conditions to determine whether the relevant information of adjacent blocks can be used as predictors for the current coding block.

[0123] According to some embodiments, if an adjacent block is encoded in the same prediction mode as the current block, the adjacent block can be used to predict the current block.

[0124] In one embodiment, when the current block is encoded in the IBC prediction mode, an adjacent block encoded in the IBC prediction mode can be used to predict the current block. When it is determined that an adjacent block is available (as described in further detail below), the prediction information (e.g., block vector) from the adjacent block will be included in the prediction list for the IBC prediction mode.

[0125] In another embodiment, when the current block is encoded in the inter prediction mode, an adjacent block encoded in the inter prediction mode can be used to predict the current block. When it is determined that an adjacent block is available (as described in further detail below), the prediction information (e.g., motion vector, reference index, prediction direction, etc.) from the adjacent block will be included in the prediction list for the inter prediction mode.

[0126] In another embodiment, when the current block is encoded in the intra prediction mode, an adjacent block encoded in the intra prediction mode can be used to predict the current block. When it is determined that an adjacent block is available (as described in further detail below), the prediction information from the adjacent block will be included in the prediction list for the intra prediction mode.

[0127] In some embodiments, the determination of the availability of an adjacent block can be divided into two steps. The first step includes checking the decoding order. In an example, if an adjacent block is in a different slice, tile, or tile group compared to the current block, it is determined that the adjacent block cannot be used to predict the current block. A slice can be a group of blocks in raster scan order, and the groups of blocks in a slice can use the same prediction mode. A tile can be a region of a picture and can be independently processed in parallel. A tile group can be a set of tiles and can share the same header among tile groups. In another example, if an adjacent block has not been reconstructed before the current block, it is determined that the adjacent block cannot be used to predict the current block.

[0128] After completing the first step (e.g., determining that an adjacent block is available according to the decoding order), a second step is applied to the adjacent block to check the prediction availability of the adjacent block. In an example, if the adjacent block overlaps with the current block (e.g., the adjacent block has not been fully constructed before the current block, at least one sample in the adjacent block has not been constructed before the current block), it is determined that the adjacent block is not available for predicting the current block. In another example, if an adjacent block is encoded in a different prediction mode from the current block, it is determined that the adjacent block is not available for predicting the current block.

[0129] According to some embodiments, if an adjacent block is encoded in the IBC prediction mode while the current block is encoded in the inter prediction mode, the adjacent block can be used to predict the current block.

[0130] According to some embodiments, if an adjacent block is encoded in an inter prediction mode while the current block is encoded in an IBC prediction mode, the adjacent block can be used to predict the current block.

[0131] In the above two determination methods, according to some embodiments, it will be checked whether the adjacent block is encoded in an intra prediction mode. If the adjacent block is encoded in the intra prediction mode, it is determined that the adjacent block cannot be used to predict the current block. In addition, some other conditions of the adjacent block (e.g., the decoding order of the adjacent block) will also be checked. In an example, if the adjacent block is in a different slice, tile, or tile group compared to the current block, it is determined that the adjacent block cannot be used to predict the current block. A slice can be a group of blocks in a raster scan order, and the groups of blocks in a slice can use the same prediction mode. A tile can be a region of a picture and can be independently processed in a parallel manner. A tile group can be a set of tiles and can share the same header between tile groups. In another example, if the adjacent block has not been reconstructed before the current block, it is determined that the adjacent block cannot be used to predict the current block. In another example, if the adjacent block overlaps with the current block, it is determined that the adjacent block cannot be used to predict the current block. In another example, if the adjacent block is encoded in a different prediction mode from the current block, it is determined that the adjacent block cannot be used to predict the current block.

[0132] In addition to the method of checking the availability of an adjacent block as a predictor of the current block, embodiments of the present disclosure include a method of determining the boundary strength of a deblocking filter for reconstructing the current block in an IBC prediction mode. When the current block is being reconstructed, the deblocking filter can be used to enhance the visual quality and prediction performance by smoothing the sharp edges of the boundaries between decoded blocks, and the boundary strength is used to indicate the intensity level at which the deblocking filter is used. In one embodiment, the intensity level "0" can indicate that the deblocking filter is not performed, while the intensity level "1" can indicate that the deblocking filter is performed. In another embodiment, more than two intensity levels are used, such as a low intensity level, a medium intensity level, and a high intensity level. By performing the deblocking filter with different intensity levels, the current block can have different visual qualities.

[0133] In the IBC prediction mode, the luminance component and the chrominance component are encoded in a coding tree structure respectively. The chrominance CU can operate in a sub-block mode. For example, the sub-blocks of the chrominance CU can be obtained from the co-located luminance positions of the sub-blocks, so different sub-blocks can have different block vectors. Therefore, according to embodiments of the present disclosure, when performing the deblocking filter on the chrominance CU, some methods can be used to determine the boundary strength of the deblocking filter.

[0134] According to some embodiments, a deblocking filter is performed on the sub-block boundaries of a chrominance CU, and the boundary strength (BS) at the sub-block boundary is determined by evaluating the difference between the corresponding chrominance block vectors of two coded sub-blocks associated with the sub-block boundary. In one embodiment, if the absolute value of the difference between the horizontal (or vertical) components of the corresponding block vectors is greater than or equal to 1, in terms of integer luminance samples (or another expression with the same meaning: 4, in terms of quarter luminance samples), then the deblocking filter will be performed. Otherwise, the deblocking filter will not be performed.

[0135] According to some embodiments, a deblocking filter is performed on the sub-block boundaries of a chrominance CU, or on larger 4×4 block boundaries. In one embodiment, if the sub-block size of the chrominance CU is 2×2, the deblocking filter is not performed at some sub-block boundaries within the 2×2 sub-block boundaries, but is performed at each boundary within the 4×4 grid boundaries. For these 4×4 boundaries, the boundary strength (BS) at the boundary can be determined by evaluating the difference between the corresponding block vectors of two coded sub-blocks associated with the sub-block boundary. If the absolute value of the difference between the horizontal (or vertical) components of the corresponding block vectors is greater than or equal to 1, in terms of integer luminance samples (or another expression with the same meaning: 4, in terms of quarter luminance samples), then the deblocking filter will be performed. Otherwise, the deblocking filter will not be performed.

[0136] Figure 10 A flowchart showing an overview of an exemplary process (1000) according to an embodiment of the present disclosure is shown. The process (1000) can be used for the reconstruction of blocks encoded in a (e.g., inter / intra / IBC) prediction mode, so as to generate a prediction block for the block being reconstructed. In various embodiments, the process (1000) is executed by a processing circuit, such as: the processing circuit in the terminal device (210), the terminal device (220), the terminal device (230), and the terminal device (240); the processing circuit that executes the functions of the video encoder (303); the processing circuit that executes the functions of the video decoder (310); the processing circuit that executes the functions of the video decoder (410); the processing circuit that executes the functions of the intra prediction module (452); the processing circuit that executes the functions of the video encoder (503); the processing circuit that executes the functions of the predictor (535); the processing circuit that executes the functions of the intra encoder (622); the processing circuit that executes the functions of the intra decoder (772), etc. In some embodiments, the process (1000) is implemented by software instructions, so when the processing circuit executes the software instructions, the processing circuit executes the process (1000).

[0137] The process (1000) typically can start from step (S1010), where the process (1000) decodes the prediction information of the current block in the current encoded picture that is part of an encoded video sequence. The prediction information indicates a first prediction mode for the current block. The first prediction mode can be one of an intra prediction mode, an inter prediction mode, or an IBC prediction mode.

[0138] The process (1000) proceeds to step (S1020), where the process (1000) determines whether an adjacent block that is adjacent to the current block and has been reconstructed before the current block uses the first prediction mode.

[0139] The process (1000) proceeds to step (S1030), where, in response to determining that the adjacent block uses the first prediction mode, the process (1000) inserts the prediction information from the adjacent block into the prediction list for the first prediction mode.

[0140] The process (1000) proceeds to step (S1040), where the process (1000) reconstructs the current block according to the prediction list for the first prediction mode.

[0141] After reconstructing the current block, the process (1000) ends.

[0142] The above - mentioned technology can be implemented as computer software that uses computer - readable instructions and is physically stored in one or more computer - readable media. For example, Figure 11 FIG. shows a computer system (1100) suitable for implementing certain embodiments of the disclosed subject matter.

[0143] The computer software can be encoded using any suitable machine code or computer language, and any suitable machine code or computer language can be subject to mechanisms such as assembly, compilation, linking, or the like to create code including instructions that can be directly executed by one or more computer central processing units (CPUs), graphics processing units (GPUs), etc., or executed through decoding, microcode, etc.

[0144] The instructions can be executed on various types of computers or their components, such as including personal computers, tablet computers, servers, smart phones, gaming devices, Internet of Things devices, etc.

[0145] Figure 11 The components of the computer system (1100) shown in are exemplary in nature and are not intended to impose any limitation on the scope of the use or functionality of the computer software implementing the embodiments of the present disclosure. The configuration of the components should also not be construed as having any dependency or requirement related to any one component or combination of components shown in the exemplary embodiments of the computer system (1100).

[0146] A computer system (1100) may include certain human-machine interface input devices. Such human-machine interface input devices may respond to input from one or more human users through, for example, the following: tactile input (e.g., keystrokes, swipes, data glove movements), audio input (e.g., speech, clapping), visual input (e.g., gestures), olfactory input (not depicted). The human-machine interface devices may also be used to capture certain media that are not necessarily directly related to conscious human input, such as audio (e.g., speech, music, ambient sound), images (e.g., scanned images, photographic images obtained from a still image camera), video (e.g., two-dimensional video, three-dimensional video including stereoscopic video), etc.

[0147] The input human-machine interface devices may include one or more of the following (only one of each is shown): keyboard (1101), mouse (1102), touchpad (1103), touch screen (1110), data glove (not shown), joystick (1105), microphone (1106), scanner (1107), camera (1108).

[0148] The computer system (1100) 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 of the touch screen (1110), data glove (not shown), or joystick (1105), but may also be tactile feedback devices that are not used as input devices), audio output devices (e.g., speakers (1109), headphones (not depicted)), visual output devices (e.g., screens (1110) including CRT screens, LCD screens, plasma screens, OLED screens, each with or without touch screen input functionality, each with or without tactile feedback functionality - some of which are capable of outputting two-dimensional visual output or output beyond three dimensions through devices such as stereoscopic image output, virtual reality glasses (not depicted), holographic displays, and smoke boxes (not depicted), as well as printers (not depicted)).

[0149] The computer system (1100) may also include human-accessible storage devices and their associated media, such as, for example, optical media including CD / DVD ROM / RW (1120) with media such as CD / DVD (1121), thumb drives (1122), removable hard disk drives or solid state drives (1123), traditional magnetic media such as tapes and floppy disks (not depicted), devices based on dedicated ROM / ASIC / PLD such as security dongles (not depicted), etc.

[0150] Those skilled in the art should also understand that the term "computer-readable medium" used in connection with the presently disclosed subject matter does not cover a transmission medium, a carrier wave, or other transitory signals.

[0151] The computer system (1100) may also include an interface to one or more communication networks. The network may be, for example, a wireless network, a wired network, an optical network. The network may further be a local area network, a wide area network, a metropolitan area network, a vehicle and industrial network, a real-time network, a delay-tolerant network, etc. Examples of networks include local area networks such as Ethernet, wireless 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 and industrial networks including CANBus, and so on. Certain networks typically require an external network interface adapter (e.g., a USB port of the computer system (1100)) connected to certain common data ports or peripheral buses (1149); as described below, other network interfaces are typically integrated into the kernel of the computer system (1100) by connecting to the system bus (e.g., an Ethernet interface in a PC computer system or a cellular network interface in a smartphone computer system). The computer system (1100) may communicate with other entities using any of these networks. Such communication may be one-way reception only (e.g., broadcast television), one-way transmission only (e.g., CANBus connected to certain CANbus devices), or two-way, for example, using a local area network or a wide area digital network to connect to other computer systems. As described above, certain protocols and protocol stacks may be used on each of those networks and network interfaces.

[0152] The above-mentioned human-machine interface device, human-accessible storage device, and network interface may be attached to the kernel (1140) of the computer system (1100).

[0153] The kernel (1140) may include one or more central processing units (CPUs) (1141), a graphics processing unit (GPU) (1142), a dedicated programmable processing unit in the form of a field programmable gate area (FPGA) (1143), a hardware accelerator (1144) for certain tasks, etc. These devices, as well as a read-only memory (ROM) (1145), a random access memory (1146), an internal mass storage such as an internal hard disk drive, SSD, etc. that is not user-accessible (1147), may be connected via a system bus (1148). In some computer systems, the system bus (1148) may be accessed in the form of one or more physical plugs to enable expansion via additional CPUs, GPUs, etc. Peripheral devices may be directly connected to the system bus (1148) of the kernel or connected to the system bus (1148) of the kernel via a peripheral bus (1149). The architecture of the peripheral bus includes PCI, USB, etc.

[0154] The CPU (1141), GPU (1142), FPGA (1143), and accelerator (1144) may execute certain instructions, which may be combined to form the above-mentioned computer code. The computer code may be stored in the ROM (1145) or the RAM (1146). Transitional data may also be stored in the RAM (1146), while permanent data may be stored, for example, in the internal mass storage (1147). Fast storage and retrieval to any storage device may be performed by using a cache, which may be closely associated with one or more CPUs (1141), GPUs (1142), mass storage (1147), ROM (1145), RAM (1146), etc.

[0155] A computer-readable medium may have computer code thereon for performing various computer-implemented operations. The medium and the computer code may be media and computer code that are specially designed and constructed for the purposes of the present disclosure, or the medium and the computer code may be of the type that is well-known and available to those skilled in the art of computer software.

[0156] As a non-limiting example, a computer system having an architecture (1100), particularly a core (1140), can provide functionality due to one or more processors (including CPUs, GPUs, FPGAs, accelerators, etc.) executing software included in one or more tangible computer-readable media. Such computer-readable media can be media associated with user-accessible mass storage as described above, as well as certain non-transitory memories of the core (1140), such as on-core mass memory (1147) or ROM (1145). Software implementing embodiments of the present disclosure can be stored in such devices and executed by the core (1140). Depending on specific needs, the computer-readable media can include one or more storage devices or chips. The software can cause the core (1140), particularly 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 (1146) and modifying such data structures according to processes defined by the software. Additionally or alternatively, a computer system can provide functionality due to logic hardwired or otherwise embodied in circuitry (e.g., accelerator (1144)) that can replace software or operate in conjunction with software to execute specific processes or specific portions of specific processes described herein. In appropriate instances, portions referring to software can include logic, and vice versa. In appropriate instances, portions referring to computer-readable media can include circuitry (e.g., integrated circuit (IC)) storing software for execution, circuitry embodying logic for execution, or include both. The present disclosure encompasses any suitable combination of hardware and software.

[0157] Although the present disclosure has described multiple exemplary embodiments, there are modifications, permutations, and various alternative equivalents that fall within the scope of the present disclosure. Accordingly, it should be understood that those skilled in the art will be able to design many systems and methods that, although not explicitly shown or described herein, embody the principles of the present disclosure and thus fall within the spirit and scope of the present disclosure.

[0158] (1) A method for video decoding in a decoder, comprising: decoding prediction information for a current block in a current encoded picture that is part of an encoded video sequence, the prediction information indicating a first prediction mode for the current block; determining whether an adjacent block adjacent to and reconstructed before the current block uses the first prediction mode; in response to determining that the adjacent block uses the first prediction mode, inserting prediction information from the adjacent block into a prediction list for the first prediction mode; and reconstructing the current block according to the prediction list for the first prediction mode.

[0159] (2) The method according to feature (1), in response to determining that an adjacent block uses a second prediction mode different from the first prediction mode, further includes: determining whether the second prediction mode is an intra prediction mode; and in response to determining that the second prediction mode is not an intra prediction mode, inserting prediction information from the adjacent block into the prediction list for the first prediction mode.

[0160] (3) The method according to feature (1), further includes: determining whether an adjacent block is in the same slice as the current block, where a slice is a group of blocks in raster scan order and the groups of blocks in a slice use the same prediction mode; and in response to determining that the adjacent block is in the same slice as the current block, inserting prediction information from the adjacent block into the prediction list for the first prediction mode.

[0161] (4) The method according to feature (1), further includes: determining whether an adjacent block is in the same tile or the same tile group as the current block, where a tile is a region of a picture and is independently processed in parallel, and a tile group is a group of tiles and shares the same header among a group of tiles; and in response to determining that the adjacent block is in the same tile or the same tile group as the current block, inserting prediction information from the adjacent block into the prediction list for the first prediction mode.

[0162] (5) The method according to feature (1), further includes: determining whether an adjacent block overlaps with the current block; and in response to determining that the adjacent block does not overlap with the current block, inserting prediction information from the adjacent block into the prediction list for the first prediction mode.

[0163] (6) The method according to feature (1), wherein the first prediction mode includes at least one of an intra block copy prediction mode and an inter prediction mode.

[0164] (7) The method according to feature (6), wherein the prediction information from the adjacent block includes at least one of a block vector and a motion vector, the block vector indicates the offset between the adjacent block and the current block and is used to predict the current block when encoding the adjacent block in the intra block copy prediction mode, and the motion vector is used to predict the current block when encoding the adjacent block in the inter prediction mode.

[0165] (8) An apparatus includes a processing circuit configured to: decode prediction information for a current block in a current encoded picture that is part of an encoded video sequence, the prediction information indicating a first prediction mode for the current block; determine whether an adjacent block adjacent to the current block and reconstructed before the current block uses the first prediction mode; in response to determining that the adjacent block uses the first prediction mode, insert prediction information from the adjacent block into the prediction list for the first prediction mode; and reconstruct the current block according to the prediction list for the first prediction mode.

[0166] (9) The apparatus according to feature (8), wherein, in response to determining that an adjacent block uses a second prediction mode different from the first prediction mode, the processing circuit is further configured to: determine whether the second prediction mode is an intra prediction mode; and in response to determining that the second prediction mode is not an intra prediction mode, insert prediction information from the adjacent block into the prediction list for the first prediction mode.

[0167] (10) The apparatus according to feature (8), wherein the processing circuit is further configured to: determine whether the adjacent block is in the same slice as the current block, the slice being a group of blocks in raster scan order and the group of blocks in the slice using the same prediction mode; and in response to determining that the adjacent block is in the same slice as the current block, insert prediction information from the adjacent block into the prediction list for the first prediction mode.

[0168] (11) The apparatus according to feature (8), wherein the processing circuit is further configured to: determine whether the adjacent block is in the same tile or the same tile group as the current block, the tile being a region of a picture and processed independently in parallel, the tile group being a group of tiles and sharing the same header among a group of tiles; and in response to determining that the adjacent block is in the same tile or the same tile group as the current block, insert prediction information from the adjacent block into the prediction list for the first prediction mode.

[0169] (12) The apparatus according to feature (8), wherein the processing circuit is further configured to: determine whether the adjacent block overlaps with the current block; and in response to determining that the adjacent block does not overlap with the current block, insert prediction information from the adjacent block into the prediction list for the first prediction mode.

[0170] (13) The apparatus according to feature (8), wherein the first prediction mode includes at least one of an intra block copy prediction mode and an inter prediction mode.

[0171] (14) The apparatus according to feature (13), wherein the prediction information from the adjacent block includes at least one of a block vector and a motion vector, the block vector indicating an offset between the adjacent block and the current block and being used to predict the current block when encoding the adjacent block in the intra block copy prediction mode, and the motion vector being used to predict the current block when encoding the adjacent block in the inter prediction mode.

[0172] (15)A non-transitory computer-readable storage medium stores a program that can be executed by at least one processor to perform: decoding prediction information of a current block in a current encoded picture that is part of an encoded video sequence, the prediction information indicating a first prediction mode for the current block; determining whether an adjacent block adjacent to the current block and reconstructed before the current block uses the first prediction mode; in response to determining that the adjacent block uses the first prediction mode, inserting the prediction information from the adjacent block into a prediction list for the first prediction mode; and reconstructing the current block according to the prediction list for the first prediction mode.

[0173] (16)The non-transitory computer-readable storage medium according to feature (15), wherein, in response to determining that the adjacent block uses a second prediction mode different from the first prediction mode, the stored program further performs: determining whether the second prediction mode is an intra prediction mode; and in response to determining that the second prediction mode is not an intra prediction mode, inserting the prediction information from the adjacent block into the prediction list for the first prediction mode.

[0174] (17)The non-transitory computer-readable storage medium according to feature (15), wherein the stored program further performs: determining whether the adjacent block and the current block are in the same slice, the slice being a group of blocks in raster scan order and the groups of blocks in the slice using the same prediction mode; and in response to determining that the adjacent block and the current block are in the same slice, inserting the prediction information from the adjacent block into the prediction list for the first prediction mode.

[0175] (18)The non-transitory computer-readable storage medium according to feature (15), wherein the stored program further performs: determining whether the adjacent block and the current block are in the same tile or the same tile group, the tile being a region of the picture and processed independently in parallel, the tile group being a group of tiles and sharing the same header; and in response to determining that the adjacent block and the current block are in the same tile or the same tile group, inserting the prediction information from the adjacent block into the prediction list for the first prediction mode.

[0176] (19)The non-transitory computer-readable storage medium according to feature (15), wherein the stored program further performs: determining whether the adjacent block overlaps with the current block; and in response to determining that the adjacent block does not overlap with the current block, inserting the prediction information from the adjacent block into the prediction list for the first prediction mode.

[0177] (20)The non-transitory computer-readable storage medium according to feature (15), wherein the first prediction mode includes at least one of an intra block copy prediction mode and an inter prediction mode.

[0178] Appendix A: Abbreviations

[0179] AMVP: Advanced Motion Vector Prediction

[0180] ASIC: Application Specific Integrated Circuit

[0181] BMS: Benchmark Set

[0182] BV: Block Vector

[0183] CANBus: Controller Area Network Bus

[0184] CD: Compact Disc

[0185] CPR: Current Picture Reference

[0186] CPU: Central Processing Unit

[0187] CRT: Cathode Ray Tube

[0188] CTB: Coding Tree Block

[0189] CTU: Coding Tree Unit

[0190] CU: Coding Unit

[0191] DPB: Decoder Picture Buffer

[0192] DVD: Digital Video Disc

[0193] FPGA: Field Programmable Gate Array

[0194] GOP: Group of Pictures

[0195] GPU: Graphics Processing Unit

[0196] GSM: Global System for Mobile Communications

[0197] HEVC: High Efficiency Video Coding

[0198] HRD: Hypothetical Reference Decoder

[0199] IBC: Intra Block Copy

[0200] IC: Integrated Circuit

[0201] JEM: Joint Exploration Model

[0202] LAN: Local Area Network

[0203] LCD: Liquid Crystal Display

[0204] LTE: Long Term Evolution

[0205] MV: Motion Vector

[0206] OLED: Organic Light Emitting Diode

[0207] PB: Prediction Block

[0208] PCI: Peripheral Component Interconnect

[0209] PLD: Programmable Logic Device

[0210] PU: Prediction Unit

[0211] RAM: Random Access Memory

[0212] ROM: Read-Only Memory

[0213] SCC: Screen Content Coding

[0214] SEI: Supplemental Enhancement Information

[0215] SNR: Signal-to-Noise Ratio

[0216] SSD: Solid State Drive

[0217] TU: Transform Unit

[0218] USB: Universal Serial Bus

[0219] VUI: Video Usability Information

[0220] VVC: Versatile Video Coding

Claims

1. A method for video encoding, characterized in that, The method includes: Determining prediction information for a current block in a current picture, where the prediction information indicates a first prediction mode for the current block; the first prediction mode includes an intra-block copy prediction mode; Checking whether an adjacent block is encoded in an intra prediction mode, where the adjacent block is adjacent to the current block and has been encoded before the current block; Based on the following conditions, inserting prediction information from the adjacent block into a prediction list for the current block: (i) The adjacent block does not adopt the intra prediction mode; (ii) Both the adjacent block and the current block adopt the intra-block copy prediction mode; and (iii) The adjacent block and the current block are in the same slice, the same tile, or the same tile group; and Encoding the current block according to the prediction list.

2. The method according to claim 1, characterized in that The method further includes: The slice is a group of blocks in raster scan order and the groups of blocks in the slice use the same prediction mode.

3. The method according to claim 1, characterized in that The method further includes: The tile is a region of the picture and is processed independently in parallel; the tile group is a group of tiles and shares the same header among the group of tiles.

4. The method according to claim 1, wherein The method further includes: Determining whether the adjacent block overlaps with the current block; and In response to determining that the adjacent block does not overlap with the current block, inserting prediction information from the adjacent block into the prediction list for the first prediction mode.

5. The method according to claim 1, wherein The prediction information includes at least one of a block vector and a motion vector, the block vector indicating an offset between the adjacent block and the current block and being used to predict the current block when encoding the adjacent block in an intra-block copy prediction mode; and the motion vector is used to predict the current block when encoding the adjacent block in an inter prediction mode.

6. A video encoding device, characterized in that, The apparatus includes a processing circuit configured to: Determine prediction information for a current block in a current picture, where the prediction information indicates a first prediction mode for the current block; the first prediction mode includes an intra-block copy prediction mode; Check whether an adjacent block is encoded in an intra prediction mode, where the adjacent block is adjacent to the current block and has been encoded before the current block; Based on the following conditions, insert prediction information from the adjacent block into a prediction list for the current block: (i) The adjacent block does not adopt the intra prediction mode; (ii) Both the adjacent block and the current block adopt the intra-block copy prediction mode; and (iii) The adjacent block and the current block are in the same slice, the same tile, or the same tile group; and Encode the current block according to the prediction list.

7. The device according to claim 6, characterized in that, The processing circuit is further configured to: The slice is a group of blocks in raster scan order and the groups of blocks in the slice use the same prediction mode.

8. The device according to claim 6, characterized in that, The processing circuit is further configured to: The tile is a region of the picture and is processed independently in parallel; the tile group is a group of tiles and shares the same header among the group of tiles.

9. The device according to claim 6, characterized in that The processing circuit is further configured to: Determine whether the adjacent block overlaps with the current block; and In response to determining that the adjacent block does not overlap with the current block, insert the prediction information from the adjacent block into the prediction list for the first prediction mode.

10. The apparatus according to claim 6, wherein The prediction information includes at least one of a block vector and a motion vector. The block vector indicates the offset between the adjacent block and the current block and is used to predict the current block when encoding the adjacent block in the intra-block copy prediction mode; and the motion vector is used to predict the current block when encoding the adjacent block in the inter prediction mode.

11. A method for video decoding, characterized in that, The method includes: Determine the prediction information of a current block in a current picture of a video sequence, wherein the prediction information indicates that the current block adopts an intra-block copy (IBC) prediction mode; Determine whether an adjacent block adopts an intra prediction mode, wherein the adjacent block is adjacent to the current block and has been encoded before the current block; Based on the following conditions, insert the prediction information from the adjacent block into the prediction list for the current block: (i) The adjacent block does not adopt the intra prediction mode; (ii) Both the adjacent block and the current block adopt the IBC prediction mode; and (iii) The adjacent block and the current block are in the same slice, the same tile or the same tile group; and Decode the current block according to the prediction list.

12. A computer device, comprising: A processor and a memory for storing a computer program that can run on the processor; Wherein, when the processor is used to run the computer program, it implements the video encoding and decoding method according to any one of claims 1 to 4, 11.

13. A non-transitory computer-readable storage medium storing a program, the program being executed by at least one processor to execute the video encoding and decoding method according to any one of claims 1 to 11.

14. A method for storing a bitstream, characterized in that, The bitstream is generated according to the video encoding method according to any one of claims 1 to 5.

Images