Multiple lists of block-based weight factors

Abstract

The various implementations described herein include methods and systems for coding video. In one embodiment, the method includes the steps of receiving a video bitstream containing the current coding block of the current image frame, and determining that the current coding block should be predicted in weighted bi-prediction (WBP) mode. The method further includes, in response to the current coding block being predicted in WBP mode, determining that the current coding block is associated with two bi-prediction blocks, and identifying a plurality of separate weight factor lists containing a first list of at least positive weight factors and a second list of mixed weight factors. The method further includes the steps of reconstructing the current image frame, which include selecting one of the weight factor lists, identifying a first weight factor from the weight factor list, and determining the current coding block by combining the two bi-prediction blocks based on the first weight factor.

Description

Technical Field

[0001] Related Applications This application claims priority to U.S. Provisional Patent Application No. 63 / 453,697, filed on March 21, 2023, entitled "Multiple Lists for Block Based Weighting Factors", and this application is also a continuation of U.S. Patent Application No. 18 / 217,893, filed on July 3, 2023, entitled "Multiple Lists for Block Based Weighting Factors", and claims the priority of the U.S. patent application. All of this is hereby incorporated by reference in its entirety.

[0002] The disclosed embodiments generally relate to video coding and include, but are not limited to, systems and methods for determining weighting factors for prediction blocks of coding units in a weighted bi-prediction (WBP) mode for inter-prediction of video data.

Background Art

[0003] Digital video is supported by various electronic devices such as digital televisions, laptop or desktop computers, tablet computers, digital cameras, digital recording devices, digital media players, video game consoles, smartphones, video teleconference devices, video streaming devices. Electronic devices transmit and receive digital video data over communication networks or communicate in other ways, and / or store digital video data in storage devices. Since the bandwidth capacity of communication networks is limited and the memory resources of storage devices are limited, video coding may be used to compress video data according to one or more video coding standards before the video data is communicated or stored.

[0004] Multiple video codec standards have been developed. For example, video coding standards include AOMedia Video 1 (AV1), Versatile Video Coding (VVC), Joint Exploration Test Model (JEM), High-Efficiency Video Coding (HEVC / H.265), Advanced Video Coding (AVC / H.264), and Moving Picture Expert Group (MPEG) coding. Video coding generally utilizes prediction methods (e.g., inter-prediction, intra-prediction) that take advantage of the redundancy inherent in video data. Video coding aims to compress video data into a format that uses a lower bitrate while avoiding or minimizing a decrease in video quality.

[0005] HEVC, also known as H.265, is a video compression standard designed as part of the MPEG-H project. The ITU-T and ISO / IEC published the HEVC / H.265 standard in 2013 (version 1), 2014 (version 2), 2015 (version 3), and 2016 (version 4). Multipurpose Video Coding (VVC), also known as H.266, is a video compression standard intended as a successor to HEVC. The ITU-T and ISO / IEC published the VVC / H.266 standard in 2020 (version 1) and 2022 (version 2). AV1 is an open video coding format designed as an alternative to HEVC. A valid version 1.0.0, including Errata 1 of this specification, was released on January 8, 2019. [Overview of the project] [Problems that the invention aims to solve]

[0006] As mentioned above, encoding (compression) reduces bandwidth and / or storage space requirements. Both lossless and lossy compression can be employed, as will be discussed in more detail later. Lossless compression refers to a technique where an exact copy of the original signal can be reconstructed from the compressed original signal through the decoding process. Lossy compression refers to a coding / decoding process where the original video information is not fully preserved during coding and cannot be fully restored during decoding. When using lossy compression, the reconstructed signal may not be identical to the original signal, but the distortion between the original and reconstructed signals is small enough to make the reconstructed signal useful for its intended purpose. The acceptable amount of distortion depends on the application. For example, users of certain consumer video streaming applications may tolerate higher distortion than users of film or television broadcast applications. The compression ratio achievable by a particular coding algorithm can be selected or adjusted to reflect various distortion tolerances; that is, generally, the greater the acceptable distortion, the more possible coding algorithms that yield higher loss and higher compression ratios.

[0007] This disclosure describes determining the weight factors of a coding unit's prediction block using multiple weight factor lists in a WBP mode for inter-prediction of video data. The WBP mode is applied to generate motion compensation data for the current coding block based on two prediction blocks belonging to the same picture group (GOP) as the current coding block. The target weight factor list includes multiple weight factors from which a target weight factor can be selected to reconstruct the current coding block as a weighted combination of the two prediction blocks. In some situations, a relatively low delay in the reconstruction of the current coding block is acceptable, and the target weight factor list includes only a single negative weight factor. Conversely, in some embodiments, the multiple weight factor lists include two or more mixed weight factor lists, each having at least one negative weight factor, and the target weight factor list for the current coding block is selected from the multiple weight factor lists. Furthermore, in some embodiments, the multiple weight factor lists include two or more positive weight factor lists. The selection of the target weight factor list is optional and based on one or more of the following: the orientation of the two prediction blocks, the motion vector predictor (MVP) of one of the two prediction blocks, and the prediction distances of the reference image frame and the current image frame. Multiple weight factor lists propose different lists of weight factors from which a target weight factor list can be selected to facilitate the joining of two prediction blocks under different application scenarios. The target weight factor list is used to optimize the performance of the reconstruction process of the current coding block (e.g., image quality, image size, reconstruction rate, power consumption, data bandwidth, frame buffer size) based on different application scenarios. [Means for solving the problem]

[0008] According to several embodiments, a method for video decoding is provided. The method includes receiving a video bitstream containing the current coding block of the current image frame, and determining that the current coding block should be predicted in WBP mode. In response to the current coding block being predicted in WBP mode, the method further includes determining that the current coding block is associated with two dual prediction blocks containing a first prediction block and a second prediction block, and identifying a plurality of distinct weight factor lists containing at least a first list and a second list. The first list has all positive weight factors. The second list has mixed weight factors containing at least one negative weight factor, and the first list has at least one weight factor different from each of the weight factors in the second list. The method further includes selecting one of a plurality of weight factor lists based on a predetermined criterion, and identifying a first weight factor from the selected one of the plurality of weight factor lists. The method further includes reconstructing the current image frame, which includes determining the current coding block by combining the first prediction block and the second prediction block based on the first weight factor.

[0009] According to several embodiments, a method for video coding is provided. The method includes the step of determining that the current coding block of the current image frame should be coded in WBP mode. The method further includes the step of determining, in response that the current coding block is coded in WBP mode, that the current coding block is associated with two dual prediction blocks, including a first prediction block and a second prediction block, and identifying a plurality of separate weight factor lists, each including a first list of at least positive weight factors and a second list of mixed weight factors. The second list has at least one negative weight factor, and the first list has at least one weight factor different from each of the weight factors in the second list. The method further includes the step of selecting one of the plurality of weight factor lists based on a predetermined criterion, identifying a first weight factor from the selected one of the plurality of weight factor lists, and estimating the current coding block by combining the first prediction block and the second prediction block based on the first weight factor. The method further includes the step of generating a video bitstream containing the current coding block of the current image frame.

[0010] According to some embodiments, computing systems such as streaming systems, server systems, personal computer systems, or other electronic devices are provided. The computing system includes a control circuit and a memory for storing one or more instruction sets. The one or more instruction sets include instructions for performing any of the methods described herein. In some embodiments, the computing system includes encoder components and / or decoder components.

[0011] According to some embodiments, a non-temporary computer-readable storage medium is provided. The non-temporary computer-readable storage medium stores one or more instruction sets for execution by a computing system. One or more instruction sets include instructions for executing any of the methods described herein.

[0012] Accordingly, devices and systems having methods for coding video are disclosed. Such methods, devices, and systems may complement or replace conventional methods, devices, and systems for coding video.

[0013] The features and advantages described herein are not necessarily exhaustive, and in particular, several additional features and advantages will be apparent to those skilled in the art in consideration of the drawings, specification and claims provided herein. Furthermore, it should be noted that the language used herein has been chosen primarily for readability and explanatory purposes and is not necessarily chosen to describe or limit the subject matter described herein.

[0014] To enable a more detailed understanding of this disclosure, a more detailed description can be provided by referring to the features of various embodiments, some of which are shown in the accompanying drawings. However, the accompanying drawings are merely illustrative of the relevant features of this disclosure and should not necessarily be considered limiting, as other effective features can be recognized by those skilled in the art as they will understand by reading this disclosure. [Brief explanation of the drawing]

[0015] [Figure 1] This block diagram shows an exemplary communication system in several embodiments. [Figure 2A] This is a diagram showing exemplary elements of encoder components according to several embodiments. [Figure 2B] A directory diagram showing exemplary elements of decoder components according to several embodiments. [Figure 3] This is a diagram illustrating exemplary server systems in several embodiments. [Figure 4]The following describes an exemplary weighted biprediction scheme applied to generate a current coding block having two predictive blocks located in the same direction as the current coding block of a group of pictures, according to several embodiments. [Figure 5] This describes another exemplary weighted biprediction scheme that, according to several embodiments, is applied to generate a current coding block having two prediction blocks located in the opposite direction to the current coding block in a picture group. [Figure 6] This is a flowchart illustrating a method for coding video, based on several embodiments. [Modes for carrying out the invention]

[0016] By convention, the various features shown in the drawings are not necessarily drawn to scale, and the same reference numbers may be used to indicate similar features throughout the specification and drawings.

[0017] Various embodiments of this application relate to determining the weight factors of prediction blocks of a coding unit using multiple weight factor lists in a WBP mode for inter-prediction of video data. The WBP mode is applied to generate motion compensation data for the current coding block based on two prediction blocks belonging to the same GOP as the current coding block. The target weight factor list includes multiple weight factors from which the target weight factors are selected to reconstruct the current coding block as a weighted combination of the two prediction blocks. In some situations, the target weight factor list includes only a single negative weight factor. Conversely, in some embodiments, the multiple weight factor lists include two or more mixed weight factor lists, each having at least one negative weight factor, and the target weight factor list for the current coding block is selected from the multiple weight factor lists. Furthermore, in some embodiments, the multiple weight factor lists include two or more positive weight factor lists. The selection of the target weight factor list is optional and based on one or more of the following: the orientation of the two prediction blocks, the MVP of one of the two prediction blocks, and the prediction distances of the reference image frame and the current image frame. Multiple weight factor lists propose different lists of weight factors from which the target weight factor list is selected, in order to facilitate the joining of two prediction blocks under different application scenarios. The target weight factor list is used to optimize the performance of the reconstruction process of the current coding block (e.g., image quality, image size, reconstruction rate, power consumption, data bandwidth, frame buffer size) based on different application scenarios.

[0018] FIG. 1 is a block diagram showing a communication system 100 according to some embodiments. The communication system 100 includes a source device 102 and a plurality of electronic devices 120 (e.g., electronic devices 120-1 to electronic devices 120-m) communicatively coupled to each other via one or more networks. In some embodiments, the communication system 100 is a streaming system for use in video-enabled applications such as, for example, video conferencing applications, digital TV applications, and media storage and / or distribution applications.

[0019] The source device 102 includes a video source 104 (e.g., a camera component or a media storage) and an encoder component 106. In some embodiments, the video source 104 is a digital camera (e.g., configured to generate an uncompressed video sample stream). The encoder component 106 generates one or more encoded video bitstreams from the video stream. The video stream from the video source 104 may have a high data volume compared to the encoded video bitstream 108 generated by the encoder component 106. The encoded video bitstream 108 has a lower data volume (less data) compared to the video stream from the video source, so the encoded video bitstream 108 requires less bandwidth for transmission and less storage space for storage compared to the video stream from the video source 104. In some embodiments, the source device 102 does not include an encoder component 106 (e.g., configured to transmit uncompressed video data to the network 110).

[0020] One or more networks 110 represent any number of networks that transmit information between the source device 102, the server system 112, and / or the electronic device 120, including, for example, wired and / or wireless communication networks. One or more networks 110 may exchange data over circuit-switched channels and / or packet-switched channels. Typical networks include telecommunications networks, local area networks, wide area networks, and / or the Internet.

[0021] One or more networks 110 include a server system 112 (e.g., a distributed / cloud computing system). In some embodiments, the server system 112 is or includes a streaming server (configured to store and / or deliver video content, e.g., an encoded video stream from a source device 102). The server system 112 includes a coder component 114 (configured to encode and / or decode video data, e.g., video data). In some embodiments, the coder component 114 includes an encoder component and / or a decoder component. In various embodiments, the coder component 114 is instantiated as hardware, software, or a combination thereof. In some embodiments, the coder component 114 is configured to decode an encoded video bitstream 108 and re-encode the video data using different encoding standards and / or methods to produce encoded video data 116. In some embodiments, the server system 112 is configured to generate multiple video formats and / or encodings from the encoded video bitstream 108.

[0022] In some embodiments, server system 112 functions as a media - aware network element (MANE). For example, server system 112 may be configured to prune encoded video bitstream 108 to adapt potentially different bitstreams to one or more of electronic devices 120. In some embodiments, a MANE is provided separate from server system 112.

[0023] Electronic device 120 - 1 includes decoder component 122 and display 124. In some embodiments, decoder component 122 is configured to decode encoded video data 116 to generate an output video stream that can be rendered on a display or other type of rendering device. In some embodiments, one or more of electronic devices 120 do not include a display component (e.g., communicatively coupled to an external display device and / or including media storage). In some embodiments, electronic device 120 is a streaming client. In some embodiments, electronic device 120 is configured to access server system 112 to obtain encoded video data 116.

[0024] The source device and / or the plurality of electronic devices 120 may also be referred to as "terminal devices" or "user devices". In some embodiments, one or more of source device 102 and / or electronic devices 120 are instances of server systems, personal computers, portable devices (e.g., smartphones, tablets, or laptops), wearable devices, video conferencing devices, and / or other types of electronic devices.

[0025] In an exemplary operation of the communication system 100, source device 102 transmits an encoded video bitstream 108 to server system 112. For example, source device 102 may encode a stream of pictures captured by the source device. Server system 112 receives the encoded video bitstream 108 and may decode and / or encode the encoded video bitstream 108 using coder components 114. For example, server system 112 may apply the most suitable encoding to the video data for network transmission and / or storage. Server system 112 may transmit the encoded video data 116 (e.g., one or more encoded video bitstreams) to one or more electronic devices 120. Each electronic device 120 may decode the encoded video data 116 to restore the video picture and optionally display it.

[0026] In some embodiments, the transmission described above is unidirectional data transmission. Unidirectional data transmission may be used in media serving applications, etc. In some embodiments, the transmission described above is bidirectional data transmission. Bidirectional data transmission may be used in video conferencing applications, etc. In some embodiments, the encoded video bitstream 108 and / or encoded video data 116 are encoded and / or decoded according to one of the video coding / compression standards described herein, such as HEVC, VVC, and / or AV1.

[0027] Figure 2A is a block diagram showing exemplary elements of an encoder component 106 according to several embodiments. The encoder component 106 receives a source video sequence from a video source 104. In some embodiments, the encoder component includes a receiver (e.g., a transceiver) component configured to receive the source video sequence. In some embodiments, the encoder component 106 receives a video sequence from a remote video source (e.g., a video source which is a component of a device different from the encoder component 106). The video source 104 may provide the source video sequence in the form of a digital video sample stream which can be any suitable bit depth (e.g., 8-bit, 10-bit, or 12-bit), any color space (e.g., BT.601 Y CrCb, or RGB), and any suitable sampling structure (e.g., Y CrCb 4:2:0 or Y CrCb 4:4:4). In some embodiments, the video source 104 is a storage device that stores previously captured / prepared video. In some embodiments, the video source 104 is a camera that captures local image information as a video sequence. Video data may be provided as a series of separate pictures that convey motion when viewed sequentially. The pictures themselves may be organized as a spatial array of pixels, each pixel containing one or more samples depending on the sampling structure, color space, etc., used. Those skilled in the art will readily understand the relationship between pixels and samples. The following description focuses on samples.

[0028] The encoder component 106 is configured to encode and / or compress pictures from a source video sequence into a coded video sequence 216 in real time or under other time constraints required by the application. One function of the controller 204 is to implement an appropriate coding speed. In some embodiments, the controller 204 controls and is functionally coupled to other functional units described below. Parameters set by the controller 204 may include rate control-related parameters (e.g., lambda values ​​for picture skipping, quantizer, and / or rate distortion optimization techniques), picture size, picture group (GOP) layout, maximum motion vector search range, etc. Those skilled in the art will readily be able to identify other functions of the controller 204 that may be related to the encoder component 106 optimized for a particular system design.

[0029] In some embodiments, the encoder component 106 is configured to operate in a coding loop. In a simplified example, the coding loop includes a source coder 202 (responsible for generating symbols, such as a symbol stream, based, for example, the input picture to be coded and one or more reference pictures) and a (local) decoder 210. The decoder 210, like the (remote) decoder (when the compression between the symbols and the coded video bitstream is reversible), reconstructs the symbols to generate sample data. The reconstructed sample stream (sample data) is input to the reference picture memory 208. Since decoding the symbol stream yields bit-exact results regardless of the decoder's location (local or remote), the contents of the reference picture memory 208 are also bit-exact between the local encoder and the remote encoder. In this way, the predictive unit of the encoder interprets the same sample values ​​as reference picture samples that the decoder interprets when using predictions during decoding. This principle of reference picture synchronization (and the resulting drift if synchronization cannot be maintained due to, for example, channel errors) is known to those skilled in the art.

[0030] The operation of decoder 210 may be the same as that of a remote decoder, such as decoder component 122, which is described in detail below in relation to Figure 2B. However, referring briefly to Figure 2B, since symbols are available and the encoding / decoding of symbols to the coded video sequence by entropy coder 214 and parser 254 may be reversible, the entropy decoding portion of decoder component 122, including buffer memory 252 and parser 254, does not need to be fully implemented in local decoder 210.

[0031] At this point, it can be said that any decoder techniques present within the decoder, excluding analysis / entropy decoding, must also necessarily exist in substantially the same functional form in the corresponding encoder. For this reason, the subject matter of this disclosure focuses on the operation of the decoder. The description of encoder techniques can be omitted because it is the reverse of the decoder techniques, in which encoder techniques are described comprehensively. More detailed explanations are necessary only in specific areas, which are shown below.

[0032] As part of its operation, the source coder 202 may perform motion-compensated predictive coding, which predictively codes the input frame by referencing one or more previously coded frames from a video sequence designated as reference image frames. In this way, the coding engine 212 codes the difference between the pixel blocks of the input frame and the pixel blocks of the reference image frame that may be selected as the predictive reference to the input frame. The controller 204 may manage the coding operation of the source coder 202, including, for example, setting parameters and subgroup parameters used to encode the video data.

[0033] The decoder 210 decodes the coded video data of a frame that may be designated as a reference image frame, based on symbols created by the source coder 202. The operation of the coding engine 212 may preferably be a lossy process. When the coded video data is decoded by a video decoder (not shown in Figure 2A), the reconstructed video sequence may be a replica of the source video sequence with some errors. The decoder 210 may reproduce the decoding process that may be performed by a remote video decoder on the reference image frame and store the reconstructed reference image frame in the reference picture memory 208. In this way, the encoder component 106 locally stores a copy of the reconstructed reference image frame that has common content as the reconstructed reference image frame that will be acquired by a remote video decoder (without transmission errors).

[0034] The predictor 206 may perform a predictive search for the coding engine 212. That is, for a new frame to be coded, the predictor 206 may search the reference picture memory 208 for sample data (as candidate reference pixel blocks) or specific metadata such as reference picture motion vectors and block shapes that can serve as appropriate predictive references for the new picture. The predictor 206 may operate on sample blocks pixel by pixel to find appropriate predictive references. In some cases, the input picture may have predictive references drawn from multiple reference pictures stored in the reference picture memory 208, as determined by the search results obtained by the predictor 206.

[0035] The outputs of all the aforementioned functional units can undergo entropy coding within the entropy coder 214. The entropy coder 214 converts the symbols generated by the various functional units into coded video sequences by reversibly compressing the symbols according to techniques known to those skilled in the art (e.g., Huffman coding, variable-length coding, and / or arithmetic coding).

[0036] In some embodiments, the output of the entropy coder 214 is coupled to a transmitter. The transmitter may be configured to buffer (one or more) coded video sequences generated by the entropy coder 214 and prepare them for transmission over a communication channel 218, which may be a hardware / software link to a storage device that stores the coded video data. The transmitter may be configured to merge the coded video data from the source coder 202 with other data to be transmitted, such as coded audio data and / or auxiliary data streams (source not shown). In some embodiments, the transmitter may transmit additional data along with the coded video. The source coder 202 may include such data as part of the coded video sequence. The additional data may include time / space / SNR enhancement layers, other forms of redundant data such as redundant pictures and slices, Supplemental Enhancement Information (SEI) messages, Visual Usability Information (VUI) parameter set fragments, and the like.

[0037] The controller 204 may manage the operation of the encoder component 106. During coding, the controller 204 may assign a specific coded picture type to each coded picture, which may affect the coding technique applied to each picture. For example, a picture may be assigned as an intra-picture (I-picture), a predictive picture (P-picture), or a bidirectional predictive picture (B-picture). An intra-picture can be coded and decoded without using any other frame in the sequence as a source for prediction. Some video codecs enable various types of intra-pictures, including, for example, independent decoder refresh (IDR) pictures. Those skilled in the art will recognize their variations of I-pictures and their respective uses and characteristics, so they will not be repeated here. A predictive picture can be coded and decoded using intra-prediction or inter-prediction, which uses up to one motion vector and reference index to predict the sample value of each block. A bidirectional predictive picture can be coded and decoded using intra-prediction or inter-prediction, which uses up to two motion vectors and reference indexes to predict the sample value of each block. Similarly, multiple prediction pictures can use three or more reference pictures and associated metadata to reconstruct a single block.

[0038] A source picture can generally be spatially subdivided into multiple sample blocks (e.g., blocks of 4x4, 8x8, 4x8, or 16x16 samples each), and each block can be coded. Blocks can be coded predictively by referencing other (already coded) blocks, as determined by the coding assignment applied to each picture in the block. For example, blocks in picture I may be coded unpredictably, or they may be coded predictively by referencing already coded blocks of the same picture (spatial prediction or intra-prediction). Pixel blocks in picture P may be coded unpredictably via spatial prediction or via temporal prediction by referencing one previously coded reference picture. Pixel blocks in picture B may be coded unpredictably via spatial prediction or via temporal prediction by referencing one or two previously coded reference pictures.

[0039] Video can be captured as multiple source pictures (video pictures) in a time series. Intra-picture prediction (often abbreviated as intra-prediction) utilizes spatial correlations within a given picture, while inter-picture prediction utilizes (temporal or other) correlations between pictures. In one example, a particular picture being encoded / decoded, called the current picture, is divided into blocks. If a block in the current picture is similar to a reference block in a previously coded and still-buffered reference picture in the video, then the block in the current picture may be coded by a vector called a motion vector. The motion vector points to a reference block in the reference picture and may have a third dimension to identify the reference picture if multiple reference pictures are used.

[0040] The encoder component 106 may perform coding operations in accordance with a predetermined video coding technique or standard, such as any of those described herein. In these operations, the encoder component 106 may perform various compression operations, including predictive coding operations that utilize temporal and spatial redundancy in the input video sequence. Thus, the coded video data may conform to the syntax specified by the video coding technique or standard being used.

[0041] Figure 2B is a block diagram showing exemplary elements of a decoder component 122 according to several embodiments. The decoder component 122 in Figure 2B is coupled to channel 218 and display 124. In some embodiments, the decoder component 122 includes a transmitter coupled to a loop filter 256 and configured to transmit data to the display 124 (for example, via a wired or wireless connection).

[0042] In some embodiments, the decoder component 122 includes a receiver coupled to channel 218 and configured to receive data from channel 218 (e.g., via a wired or wireless connection). The receiver may be configured to receive one or more coded video sequences to be decoded by the decoder component 122. In some embodiments, the decoding of each coded video sequence is independent of other coded video sequences. Each coded video sequence may be received from channel 218, which may be a hardware / software link to a storage device that stores coded video data. The receiver receives coded video data along with other data, e.g., coded audio data and / or auxiliary data streams, which may be forwarded to their respective usage entities (not shown). The receiver may isolate coded video sequences from other data. In some embodiments, the receiver receives additional (redundant) data along with the coded video. The additional data may be included as part of one or more coded video sequences. The additional data may be used by the decoder component 122 to decode the data and / or to more accurately reconstruct the original video data. The additional data can take the form of, for example, a time layer, a spatial layer, or an SNR enhancement layer, redundant slices, redundant pictures, or forward error correction codes.

[0043] According to some embodiments, the decoder component 122 includes a buffer memory 252, a parser 254 (sometimes called an entropy decoder), a scaler / inverse unit 258, an intra-picture prediction unit 262, a motion compensation prediction unit 260, an aggregator 268, a loop filter unit 256, a reference picture memory 266, and a current picture memory 264. In some embodiments, the decoder component 122 is implemented as an integrated circuit, a series of integrated circuits, and / or other electronic circuits. In some embodiments, the decoder component 122 is implemented at least partially in software.

[0044] Buffer memory 252 is coupled between channel 218 and parser 254 (for example, to counteract network jitter). In some embodiments, buffer memory 252 is separate from decoder component 122. In some embodiments, a separate buffer memory is provided between the output of channel 218 and decoder component 122. In some embodiments, in addition to buffer memory 252 within decoder component 122 (configured, for example, to handle playout timing), a separate buffer memory is provided outside decoder component 122 (for example, to counteract network jitter). When receiving data from a storage / transfer device with sufficient bandwidth and controllability, or from an isosynchronous network, buffer memory 252 may be unnecessary or small. For use in best-effort packet networks such as the Internet, buffer memory 252 may be required, and buffer memory 252 may be relatively large, or advantageously adaptively sized, and may be at least partially implemented in an operating system or similar element (not shown) outside decoder component 122.

[0045] The parser 254 is configured to reconstruct symbols 270 from the coded video sequence. The symbols may include, for example, information used to manage the operation of decoder component 122 and / or information for controlling rendering devices such as the display 124. The control information for (one or more) rendering devices may be in the form of Supplementary Enhancement Information (SEI) messages or Video Usability Information (VUI) parameter set fragments (not shown). The parser 254 parses (entropy decodes) the coded video sequence. The coding of the coded video sequence may follow video coding techniques or standards and may follow principles well known to those skilled in the art, including variable-length coding, Huffman coding, context-dependent or non-context-dependent arithmetic coding, etc. The parser 254 may extract from the coded video sequence a set of subgroup parameters relating to at least one of the subgroups of pixels in the video decoder, based on at least one parameter corresponding to a group. Subgroups may include picture groups (GOP), pictures, tiles, slices, macroblocks, coding units (CU), blocks, transformation units (TU), and prediction units (PU). Parser 254 may extract information such as transformation factors, quantization parameter values, and motion vectors from the coded video sequence.

[0046] The reconstruction of symbol 270 may involve multiple different units, depending on the type of coded video picture or part thereof (interpicture and intrapicture, interblock and intrablock, etc.) and other factors. Which units are involved and how they are involved can be controlled by subgroup control information parsed from the video sequence coded by parser 254. The flow of such subgroup control information between parser 254 and the following multiple units is not described for illustrative purposes.

[0047] In addition to the functional blocks already mentioned, the decoder component 122 can be conceptually subdivided into several functional units, as described below. In actual implementations operating under commercial constraints, many of these units can interact closely with each other and be integrated with each other at least partially. However, for the purpose of illustrating the disclosed subject, the following conceptual subdivision into functional units is maintained.

[0048] The scaler / inverse unit 258 receives quantized transformation factors and control information as symbols 270 (e.g., which transformation to use, block size, quantization factors, and / or quantization scaling matrix) from the parser 254. The scaler / inverse unit 258 can output a block containing sample values ​​that can be input to the aggregator 268.

[0049] In some cases, the output samples of the scaler / inverse unit 258 relate to intracoded blocks, i.e., blocks that do not use predictive information from a previously reconstructed picture, but can use predictive information from a previously reconstructed portion of the current picture. Such predictive information may be provided by the intrapicture predictive unit 262. The intrapicture predictive unit 262 may generate a block of the same size and shape as the block being reconstructed, using the surrounding already reconstructed information fetched from the current (partially reconstructed) picture from the current picture memory 264. The aggregator 268 may, sample by sample, add the predictive information generated by the intrapicture predictive unit 262 to the output sample information provided by the scaler / inverse unit 258.

[0050] In other cases, the output samples of the scaler / inverse unit 258 relate to an intercoded and potentially motion-compensated block. In such cases, the motion-compensated prediction unit 260 can access the reference picture memory 266 to fetch samples to be used for prediction. After motion-compensating the fetched samples according to the symbols 270 related to the block, these samples can be added to the output of the scaler / inverse unit 258 by the aggregator 268 to generate output sample information (in this case, called residual samples or residual signals). The address in the reference picture memory 266 from which the motion-compensated prediction unit 260 fetches the predicted samples may be controlled by a motion vector. The motion vector may be available to the motion-compensated prediction unit 260 in the form of a symbol 270, which may have, for example, X, Y, and reference picture components. Motion compensation may also include interpolation of fetched sample values ​​from the reference picture memory 266 when the exact motion vector of the subsample is used, a motion vector prediction mechanism, etc.

[0051] The output samples from the aggregator 268 can undergo various loop filtering techniques in the loop filter unit 256. The video compression technique may include in-loop filtering techniques, which are controlled by parameters contained in the coded video bitstream and made available to the loop filter unit 256 as symbols 270 from the parser 254, but may also respond to metadata obtained during decoding of previous (in decoding order) portions of the coded picture or coded video sequence, or to previously reconstructed and loop-filtered sample values.

[0052] The output of the loop filter unit 256 can be output to a rendering device such as the display 124, and can also be a sample stream that can be stored in the reference picture memory 266 for use in future interpicture prediction.

[0053] A particular coded picture, once fully reconstructed, can be used as a reference picture for future predictions. Once a coded picture is fully reconstructed and identified as a reference picture (for example, by parser 254), the current reference picture can become part of reference picture memory 266, allowing for reallocation of new current picture memory before starting the reconstruction of the next coded picture.

[0054] The decoder component 122 may perform decoding operations according to a predetermined video compression technique that may be documented in a standard, such as one of the standards described herein. The coded video sequence may conform to the syntax specified by the video compression technique or standard being used, in the sense that it is faithful to the syntax of the video compression technique or standard, as specified in the video compression technique documentation or standard, specifically the profile documentation therein. Also, in order to conform to some video compression technique or standard, the complexity of the coded video sequence may 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, maximum frame rate, maximum reconstruction sample rate (e.g., measured in megasamples per second), maximum reference picture size, etc. The limits set by the level may, in some cases, be further limited by the Hypothetical Reference Decoder (HRD) specification and metadata for HRD buffer management signaled in the coded video sequence.

[0055] Figure 3 is a block diagram showing a server system 112 according to several embodiments. The server system 112 includes a control circuit 302, one or more network interfaces 304, memory 314, a user interface 306, and one or more communication buses 312 for interconnecting these components. In some embodiments, the control circuit 302 includes one or more processors (e.g., CPU, GPU, and / or DPU). In some embodiments, the control circuit includes one or more field-programmable gate arrays (FPGAs), hardware accelerators, and / or one or more integrated circuits (e.g., application-specific integrated circuits).

[0056] The network interface 304 may be configured to interface with one or more communication networks (e.g., wireless, wired, and / or optical networks). These communication networks can be local, wide-area, metropolitan, automotive, and industrial, real-time, or latency-tolerant. Examples of communication networks include local area networks such as Ethernet, cellular networks including Wi-Fi, GSM, 3G, 4G, 5G, and LTE, wired or wireless wide-area digital networks for television including cable television, satellite television, and terrestrial television, and automotive and industrial networks including CANBus. Such communications can be unidirectional, receive-only (e.g., broadcast television), transmit-only (e.g., CANbus to a specific CANbus device), or bidirectional (e.g., to other computer systems using a local or wide-area digital network). Such communications may include communications to one or more cloud computing networks.

[0057] The user interface 306 includes one or more output devices 308 and / or one or more input devices 310. The input devices 310 (one or more) may include one or more of the following: a keyboard, mouse, trackpad, touchscreen, data glove, joystick, microphone, scanner, camera, etc. The output devices 308 may include one or more of the following: an audio output device (e.g., a speaker), a visual output device (e.g., a display or monitor), etc.

[0058] Memory 314 may include high-speed random-access memory (such as DRAM, SRAM, DDR RAM, and / or other random-access solid-state memory devices) and / or non-volatile memory (such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, and / or other non-volatile solid-state storage devices). Memory 314 optionally includes one or more storage devices located remotely from the control circuit 302. Memory 314, or one or more non-volatile solid-state memory devices within Memory 314, includes a non-temporary computer-readable storage medium. In some embodiments, Memory 314, or the non-temporary computer-readable storage medium of Memory 314, stores the following programs, modules, instructions, and data structures, or subsets or supersets thereof: ● An operating system that handles various basic system services and includes procedures for performing hardware-dependent tasks.316 ● A network communication module 318 used to connect the server system 112 to other computing devices via one or more network interfaces 304 (for example, via wired and / or wireless connections); ● A coding module 320 for performing various functions related to the encoding and / or decoding of data such as video data. In some embodiments, the coding module 320 is an instance of the coder component 114. The coding module 320 includes, but is not limited to, one or more of the following: Regarding the decoder component 122, a decoding module 322 performs various functions related to decoding the encoded data as described above; ○ Encoding module 340 for performing various functions related to encoded data as described above, with respect to encoder component 106; ●A picture memory 352 for storing pictures and picture data, for use with, for example, a coding module 320. In some embodiments, the picture memory 352 includes one or more of the following: a reference picture memory 208, a buffer memory 252, a current picture memory 264, and a reference picture memory 266.

[0059] In some embodiments, the decoding module 322 includes a parsing module 324 (for example, configured to perform the various functions described above with respect to the parser 254), a transformation module 326 (for example, configured to perform the various functions described above with respect to the scalar / inverse transformation unit 258), a prediction module 328 (for example, configured to perform the various functions described above with respect to the motion compensation prediction unit 260 and / or intrapicture prediction unit 262), and a filter module 330 (for example, configured to perform the various functions described above with respect to the loop filter 256).

[0060] In some embodiments, the coding module 340 includes a code module 342 (for example, configured to perform the various functions described above with respect to the source coder 202 and / or coding engine 212) and a prediction module 344 (for example, configured to perform the various functions described above with respect to the predictor 206). In some embodiments, the decoding module 322 and / or the coding module 340 includes a subset of the modules shown in Figure 3. For example, a shared prediction module is used by both the decoding module 322 and the coding module 340.

[0061] Each of the identified modules stored in memory 314 corresponds to an instruction set for performing the functions described herein. The modules identified above (e.g., instruction sets) do not need to be implemented as separate software programs, procedures, or modules, and therefore various subsets of these modules may be combined or otherwise rearranged in various embodiments. For example, the coding module 320 may optionally not include separate decoding and coding modules, but rather use the same set of modules to perform both sets of functions. In some embodiments, memory 314 stores a subset of the modules and data structures identified above. In some embodiments, memory 314 stores additional modules and data structures not described above, such as an audio processing module.

[0062] In some embodiments, the server system 112 includes a web server or a Hypertext Transfer Protocol (HTTP) server, a File Transfer Protocol (FTP) server, and web pages and applications implemented using Common Gateway Interface (CGI) scripts, PHP Hyper-text Preprocessor (PHP), Active Server Pages (ASP), Hyper Text Markup Language (HTML), Extensible Markup Language (XML), Java, JavaScript, Asynchronous JavaScript and XML (AJAX), XHP, Javelin, Wireless Universal Resource File (WURFL), etc.

[0063] Figure 3 shows server system 112 according to several embodiments, but Figure 3 is not a schematic diagram of the structure of the embodiments described herein, but is intended to be a functional description of various features that may be present in one or more server systems. In practice, as will also be recognized by those skilled in the art, items shown separately can be combined, and some items can be separated. For example, some items shown separately in Figure 3 can be implemented on a single server, and a single item can be implemented by one or more servers. The actual number of servers used to implement server system 112, and how functions are allocated among them, will vary from implementation to implementation and will optionally depend in part on the amount of data traffic the server system will handle during peak and average usage periods.

[0064] Figure 4 shows an exemplary WBP400 scheme applied to generate a current coding block 404 having two prediction blocks 408 located in the same direction as the current coding block 404 in the GOP, according to several embodiments. The GOP includes a sequence of image frames. The sequence of image frames includes a current image frame 402 which further includes the current coding block 404. The current coding block 404 is encoded based on prediction data of one or more coding blocks of one or more reference images 406 in the GOP. In some embodiments, WBP is applied to encode the current coding block 404. For example, the current coding block 404 is weighted and encoded based on prediction data of two prediction blocks 408A and 408B of two reference image frames 406A and 406B in the GOP. In the example, the current coding block 404 is temporarily located between the first prediction block 408A of the first reference image frame 406A and the second prediction block 408B of the second reference image frame 406B. In some situations (Figure 4), one of the prediction blocks 408A and 408B precedes the current coding block 404, and the other of the reference prediction blocks 408A and 408B follows the current coding block 404. Each reference image frame 406A or 406B is either directly adjacent to the current image frame 402 or separated from the current image frame 402 by several frames. Specifically, the first prediction block 408A may optionally precede or follow the current coding block 404, and may optionally be directly adjacent to the current coding block 404 or separated from it by several frames.

[0065] In some embodiments, the HEVC coding standard is applied, and the dual-prediction signal, including the video bitstream, is generated by averaging two prediction blocks of two different reference pictures and / or using two different motion vectors. In some embodiments, another coding standard, VVC, is applied, and the WBP mode is extended to allow averaging of two prediction blocks 408A and 408B in a weighted manner to go beyond averaging, as follows: P C =((8-w)*P0+w*P1+4)≫3(1) Here, P CP0 and P1 represent the predicted data for the current coding block 404, the first prediction block 408A, and the second prediction block 408B, respectively, and w is the target weighting factor applied to combine the first prediction block 408A and the second prediction block 408B (P0 and P1) in a weighted manner. In the example, a list of five mixed weight values ​​{-2,3,4,5,10} is allowed in WBP, and the target weighting factor w belongs to the list of five mixed weight values, i.e., w∈{-2,3,4,5,10}, with a unit of 1 / 8. In some cases, the list of mixed weight values ​​will contain at least one negative weighting factor (e.g., -2). If w is equal to 4, an equal weighting factor is used to average the two prediction blocks 408A and 408B. In some embodiments, for each bipredictive coding unit (e.g., the current coding block 404), the target weight factor w is determined in one of two ways. For non-merged coding units, the weight index is signaled after the motion vector difference (MVD) of the video bitstream. Alternatively, for merged coding units, the weight index is inferred from neighboring blocks based on the merge candidate index. In some embodiments, WBP is applied at the coding unit level according to the determination that each corresponding coding unit has 256 or more luma samples (i.e., according to the determination that the product of the coding unit's width and its height is 256 or greater). In some embodiments, the current image frame 402 has a delay lower than the threshold delay, and a list of mixed weight factors is used to select the target weight factor w for the current image frame 402. Alternatively, in some embodiments, the current image frame 402 has a delay not limited by the threshold delay, and a list of positive weight factors is used to select the target weight factor w for the current image frame 402. For example, a list of positive weight factors includes {3,4,5}, which is arbitrarily a subset of {-2,3,4,5,10}. In another example, a list of positive weight factors has at least one positive weight factor that is different from any of the weight factors in {-2,3,4,5,10}.

[0066] In some embodiments, the decoder 122 of the electronic device 120 (Figure 1) receives a video bitstream containing the current coding block 404 of the current image frame 402 and determines that the current coding block 402 should be predicted in WBP mode. In response to the current coding block 402 being predicted in WBP mode, the decoder 122 determines that the current coding block 402 is associated with two biprediction blocks 408, containing the first prediction block 408A of the first reference image 406A and the second prediction block 408B of the second reference image 406B. A plurality of separate weight factor lists 412 are identified, including at least a first list 412A of positive weight factors and a second list 412B of mixed weight factors. All weight factors in the first list 412A of positive weight factors are greater than 0, and the second list 412B has at least one negative weight factor (e.g., -4). The first list 412A has at least one weight factor that is different from each weight factor in the second list 412B. For example, the first list 412A is {8,12,4,10,6} and the second list is {8,12,4,20,-4}. The first list 412A has two weight factors (10 and 6) that are not included in the second list 412B. In some embodiments, the multiple distinct weight factor lists 412 further include one or more third lists 412C of mixed weight factors, each having more negative weight factors than the second list 412B.

[0067] The decoder 122 selects one of a plurality of weight factor lists 412T (i.e., target weight factor list 412T) based on a predetermined criterion 420, and identifies a first weight factor 414 (i.e., target weight factor w) from the selected one of the plurality of weight factor lists 412T. The current image frame 402 is reconstructed. The current coding block 404 is determined by combining the first prediction block 408A and the second prediction block 408B based on the first weight factor 414. In some embodiments, the first weight factor 414 is associated with the first prediction block 408A. The second weight factor 416 of the second prediction block 408B is determined based on the first weight factor 414 of the first prediction block 408A. For example, one unit selected from the plurality of weight factor lists 412T is

number

[0068] In some embodiments, upon determination that the first prediction block 408A and the second prediction block 408B have different orientations relative to the current image frame 404, the decoder 122 selects a first list 412A of positive weighting factors, for example, across a second list 412B, based on a predetermined criterion 420. For example, referring to Figure 4, the first reference image frame 406A containing the first prediction block 408A precedes the current image frame 402, and the second reference image frame 406B containing the second prediction block 408B follows the current image frame 402. The first list 412 containing only positive weighting factors is used to determine the first weighting factor 414. In some embodiments, the predetermined criterion 420 is associated with the orientation of the two prediction blocks 408 and the predicted distance of the first prediction block 408A. In accordance with the determination that the first prediction block 408A and the second prediction block 408B have different orientations relative to the current image frame 404, the decoder 122 selects a first list 412A of positive weighting factors based on the predicted distance of the first prediction block 408A. Furthermore, in some embodiments, the predicted distance is measured between (1) a first reference image frame 406A containing the first prediction block 408A and the current image frame 402 (e.g., represented as |D1-D0|), or (2) a first reference image frame 406A and a second reference image frame 406B containing the second prediction block 408B (e.g., represented as |D1-D2|), where the temporary positions of image frames 402, 406A, and 406B are represented as D0, D1, and D2. In some embodiments, the predicted distance includes image order count (POC) distances measured by several image frames.

[0069] In some embodiments, the list of weight factors 412 further includes a fourth list of positive weight factors 412D which has more weight factors than the first list of positive weight factors 412A. All weight factors in the fourth list 412D are greater than 0. The first list of positive weight factors 412A is selected to obtain the first weight factor 414 according to the determination that the predicted distance is less than the threshold distance. The fourth list of positive weight factors 412D is selected to obtain the first weight factor 414 according to the determination that the predicted distance is greater than or equal to the threshold distance. In this example, the first list 412A is {8,12,4,10,6} and the fourth list 412D is {8,12,4,10,6,14,2} which has two more positive weight factors than the first list 412A.

[0070] Alternatively, in some embodiments, a predetermined criterion 420 is associated with the orientation and syntax list indicators of two prediction blocks 408. The multiple weight factor list 412 further includes one or more fourth lists 412D of positive weight factors, in addition to a first list 412A of positive weight factors. According to the determination that the first prediction block 408A and the second prediction block 408B have different orientations with respect to the current image frame 402, the decoder 122 selects one of the first list 412A and the fourth list 412D of positive weight factors based on the syntax list indicator signaled in the current image frame 402.

[0071] Additionally or alternatively, the multiple weight factor list 412 further includes one or more fourth lists 412D of positive weight factors in addition to a first list 412A of positive weight factors. A predetermined criterion 420 is associated with the parity of the direction and motion vector predictor (MVP) indices of two prediction blocks 408. According to the determination that the first prediction block 408A and the second prediction block 408B have different directions with respect to the current image frame 402, one of the first list 412A and the fourth list 412D of positive weight factors (i.e., target weight factor list 412T) is selected based on the parity of the MVP index to select the MVP of the first prediction block 408A from a predetermined MVP list. Note that the first prediction block 408A may optionally precede or follow the current image frame 402 of the GOP. Furthermore, in some embodiments, the multiple weight factor list 412 further includes a single fourth list 412D of positive weight factors. If the MVP index is odd, decoder 122 selects one of the first list 412A and the fourth list 412D of positive weight factors. If the MVP index is even, decoder 122 selects the other of the first list 412A and the fourth list 412D of positive weight factors.

[0072] Referring to Figure 4, in the example, the first list 412A is {8,12,4,10,6}, the fourth list 412D is {8,12,4,10,6,14,2}, and the units are

number

[0073] Figure 5 shows another exemplary weighted biprediction scheme 500 applied to generate a current coding block 404 having two predictive blocks 408 located in the opposite direction to the current coding block 404 of the GOP, according to several embodiments. A decoder 122 of an electronic device 120 (Figure 1) receives a video bitstream containing the current coding block 404 of the current image frame 402 and determines that the current coding block 402 should be predicted in WBP mode. In response that the current coding block 402 was predicted in WBP mode, the decoder 122 determines that the current coding block 402 is associated with two biprediction blocks 408, including a first predictive block 408A of a first reference image 406A and a second predictive block 408B of a second reference image 406B. A plurality of distinct weight factor lists 412 are identified, including at least a first list 412A of positive weight factors and a second list 412B of mixed weight factors. All weight factors in the first list 412A of positive weight factors are greater than 0, and the second list 412B has at least positive weight factors and at least one negative weight factor (e.g., -4). The first list 412A has at least one weight factor that is different from each of the weight factors in the second list 412B. The decoder 122 selects one of a plurality of weight factor lists 412T (i.e., target weight factor list 412T) based on a predetermined criterion 420 and identifies the first weight factor 414 (i.e., target weight factor w) from the selected one of the plurality of weight factor lists 412T. The current image frame 402 is reconstructed. The current coding block 404 is determined by combining the first prediction block 408A and the second prediction block 408B based on the first weight factor 414.

[0074] In some embodiments, a predetermined criterion 420 is associated with the orientation of two prediction blocks 408 and the predicted distance of the first prediction block 408A. According to the determination that the first prediction block 408A and the second prediction block 408B have the same orientation with respect to the current image frame 402, one of a list of weight factors 412T is selected based on the predicted distance of the first prediction block 408A. Both prediction blocks 408 are either before or after the current image frame 402. The predicted distance is measured between (1) a first reference image frame 406 containing a first prediction block 408A and the current image frame 402 (e.g., represented by |D1-D0|), or (2) a first reference image frame 406A and a second reference image frame 406B containing a second prediction block 408B (e.g., represented by |D1-D2|), where the transient positions of image frames 402, 406A, and 406B are represented by D0, D1, and D2. Alternatively, in some embodiments, the multiple weight factor lists 412 further include a third list 412C of mixed weight factors having more negative weight factors than a second list 412B of mixed weight factors. For example, the second list 412B of the mixed weight factors is {8,12,4,20,-4}, and the third list 412C of the mixed weight factors is {8,12,4,18,-2,20,-4}, which has one more negative weight factor than the second list 412B. According to the determination that the predicted distance is less than the threshold distance (e.g., the distance between two image frames), the decoder 122 selects the second list 412B of the mixed weight factors. According to the determination that the predicted distance is greater than or equal to the threshold distance, the decoder 122 selects the third list 412C of the mixed weight factors.

[0075] In some embodiments, a predetermined criterion 420 is associated with the direction and syntax list indicators of two prediction blocks 408. The multiple weight factor lists 412 further include one or more third lists 412C of mixed weight factors, each having one or more negative weight factors. According to the determination that the first prediction block 408A and the second prediction block 408B have the same direction with respect to the current image frame 402, one of the second list 412B and the third list 412C of mixed weight factors is selected as the target weight factor list 412T based on the syntax list indicator signaled together with the current image frame.

[0076] In some embodiments, the multiple weight factor lists 412 further include one or more third lists 412C of mixed weight factors. Each mixed weight factor 412B or 412C has one or more positive weight factors and one or more negative weight factors. A predetermined criterion 420 is associated with the direction and motion vector predictor (MVP) index parity of two prediction blocks 408. According to the determination that the first prediction block 408A and the second prediction block 408B have the same direction with respect to the current image frame 402, one of the second list 412B and the third list 412C of mixed weight factors is selected as the target weight factor list 412T based on the parity of the MVP index, thereby selecting the MVP of the first prediction block from a predetermined MVP list. In some embodiments, the multiple weight factor lists 412 further include a single third list 412C of mixed weight factors having one or more negative weight factors. Decoder 122 selects one of the second list 412B and the third list 412C of the mixed weight factors in response to the determination that the MVP index is odd, and selects the other of the second list 412B and the third list 412C of the mixed weight factors in response to the determination that the MVP index is even.

[0077] Referring to Figure 5, in the example, the second list 412B is {8,12,4,20,-4} and the third list 412C is {8,12,4,18,-2,20,-4}. Decoder 122 determines that the MVP index is odd and selects the second list 412B of the mixed weight factors as the target weight factor list 412T, and decoder 122 determines that the MVP index is even and selects the third list 412C of the mixed weight factors as the target weight factor list 412T.

[0078] The first list of positive weight factors 412A has a first number of positive weight factors, and the second list of mixed weight factors 412B has a second number of weight factors. In some embodiments, the first number is not equal to the second number. Or, in some embodiments, the first number is equal to the second number. For example, the first list of positive weight factors is {8,12,4,10,6,14,2} and the second list of mixed weight factors is {8,12,4,18,-2,20,-4}. In another example, the first list of positive weight factors is {8,12,4,10,6} and the second list of mixed weight factors is {8,12,4,20,-4}. In yet another example, the first list of positive weight factors is {8,12,4,10,6} and the second list of mixed weight factors is {8,10,6,20,-4}.

[0079] In some embodiments, the multiple separate weight factor lists 412 correspond to sets of common weight factors included in each of the multiple separate weight factor lists. Each of the multiple separate weight factor lists 412 further includes its own set of unique weight factors. Each unique weight factor is not included in at least one of the multiple separate weight factor lists. For example, referring to Figure 5, the common set of weight factors includes 8, 12, and 4. The first list 412 includes unique weight factors 10 and 6, and the second list 412B includes unique weight factors 20 and -4.

[0080] Figure 6 is a flowchart showing a method 600 for coding video according to several embodiments. The method 600 may be implemented in a computing system (e.g., a server system 112, a source device 102, or an electronic device 120) having a control circuit and a memory for storing instructions for execution by the control circuit. In some embodiments, the method 600 is performed by executing instructions stored in the memory of the computing system (e.g., a coding module 320 of memory 314). In some embodiments, the current image frame 402 includes the current coding block 404. Weighted biprediction is applied to generate the current coding block by averaging two prediction blocks included in the same GOP as the current coding block 404 in a weighted manner. This application relates to selecting a target list of weight factors 412T from a plurality of weight factor lists 412, from which a target weight factor w(414) is further selected, based on the parameters of the current coding block 404 and the associated prediction block 408. For the current coding block 404, each of the two prediction blocks 408 is contained in a reference image frame 406 having a direction measured with reference to the current image frame 402, the direction being determined based on whether each reference image frame 406 precedes or follows the current image frame 402 according to the display order of the GOP.

[0081] In some embodiments, WBP is implemented at the block level (e.g., in coding blocks). Multiple weight factor lists 412 are applied to determine the target weight factor list 412T, from which a target weight factor (e.g., a first weight factor 414) is selected. In some embodiments, the determination of which weight factor list is used for the current coding block 404 (i.e., the target weight factor list 412T) is based on one or more of the following: the orientation of the reference image frame 406, the picture order count (POC) distance between the reference image frame 406 and the current image frame 402, the difference in quantization parameters (QP) between the reference image frame 406 and the current image frame 402, and the transient layer index of the reference image frame 406.

[0082] In some embodiments, the target weight factor list 412T is selected from at least two weight factor lists (e.g., 412A and 412B). One of the weight factor lists (e.g., 412B) has at least one negative weight factor, and one of the weight factor lists (e.g., 412A) has all positive weight factors. In other words, in some embodiments, the multiple weight factor lists 412 include at least a first list 412A of positive weight factors and a second list 412B of mixed weight factors. The first list 412A contains only positive weight factors, while the second list 412B contains at least one negative weight factor. Furthermore, in some embodiments, the target weight factor list 412T is selected from at least three weight factor lists (e.g., 412A, 412B, and 412C). All weight factors are positive integers for the first list 412A, the second list 412B contains only one weight factor with a negative integer, and the third list 412C contains two or more weight factors with negative integers. In other words, multiple weight factor lists 412 include at least a first list 412A of positive weight factors, a second list 412B of mixed weight factors, and a third list 412C of mixed weight factors. The first list 412A contains only positive weight factors, while the second list 412B contains at least one negative weight factor, and the third list 412C contains two or more negative weight factors.

[0083] In some embodiments, for example in Figure 4, according to the determination that the two reference image frames 406A and 406B have different orientations, the decoder 122 reconstructs the current coding block 404 using a weight factor list 412A having all positive integers. Otherwise, for example in Figure 5, according to the determination that the two reference image frames 406A and 406B have the same orientation with respect to the current image frame 402, the decoder 122 uses a weight factor list 412B or 412C having at least one negative integer.

[0084] In some embodiments, depending on the orientation of two reference image frames 406A and 406B and the existence of multiple weight factor lists (e.g., 412B and 412C) having negative weight factors, the decoder 122 selects a target weight factor list 412T from multiple weight factor lists 412 based on the image order count (POC) distance between the reference image frame 406 and the current image frame 402. The POC distance is measured by the number of image frames. For example, if the current coding block 404 has multiple reference image frames (e.g., 406A and 406B), each reference image frame 406 has a POC distance from the current image frame 402. Let the positions of the current image frame 402 and the reference image frames 406A and 406B be D0, D1, and D2. The POC distances of the reference image frames 406A and 406B from the current image frame 402 are shown as D0-D1 and D0-D2. The distance between point-of-concept (POC) frames 406A and 406B is denoted as D1-D2. The decoder 122 determines that one of the given POC distances (D0-D1, D0-D2, and D1-D2) is greater than the threshold distance, and selects a list with more negative weight factors as the target weight factor list (e.g., 412C).

[0085] Alternatively, in some embodiments, depending on the orientation of the two reference image frames 406A and 406B and the existence of multiple weight factor lists (e.g., 412B and 412C) having negative weight factors, the selection of which weight factor list to use for the current block (i.e., information for the target weight factor list 412T) is signaled to the bitstream and transmitted from the encoder 106 to the decoder 122. Alternatively, in some embodiments, depending on the orientation of the two reference image frames 406A and 406B and the existence of multiple weight factor lists (e.g., 412B and 412C) having negative weight factors, the target weight factor list 412T is selected from multiple weight factor lists 412 based on the index of the selected MVP in the MVP list. For example, the target weight factor list 412T is selected for the current coding block 404 based on the parity of the MVP index (for example, according to the determination of whether the index of the selected MVP in the MVP list is even or odd).

[0086] In some embodiments, the multiple weight factor lists 412 include at least two weight factor lists 412C and 412D. The list of positive weight factors 412D includes {8, 12, 4, 10, 6, 14, 2}. The list of mixed weight factors 412C includes {8, 12, 4, 18, -2, 20, -4} and has at least one negative weight factor and at least one positive weight factor. Each of the multiple weight factor lists is a unit (e.g.,

number

number

[0087] In some embodiments, the multiple weight factor lists 412 include at least two weight factor lists 412A and 412B. The first list 412A of positive weight factors includes {8,12,4,10,6}, and the second list 412B of mixed weight factors includes {8,12,4,20,-4}, having at least one negative weight factor and at least one positive weight factor. Alternatively, in some embodiments, the multiple weight factor lists 412 include at least two weight factor lists. The first list 412A of positive weight factors includes {8,12,4,10,6}, and the second list 412B of mixed weight factors includes {8,10,6,20,-4}. Alternatively and additionally, in some embodiments, the multiple weight factor lists 412 include at least three weight factor lists 412A, 412B, and 412C. The first list 412A of positive weight factors includes {8,12,4,10,6,14,2}, and the second list 412B of mixed weight factors includes {8,12,4,10,6,20,-4}. The third list 412C of mixed weight factors includes {8,12,4,18,-2,20,-4}. The third list 412C includes two negative weight factors, and the second list 412B includes a single negative weight factor. In some embodiments, the weight factors in each weight factor list 412 are arranged in a random order without affecting the selection of the target weight factor list 412T.

[0088] In some embodiments, the determination of the target weight factor list 412T is based on previously analyzed information (e.g., composite mode, motion mode, joint motion vector difference (JMVD) scaling index). In other words, in some embodiments, the target weight factor list 412T is selected from a plurality of weight factor lists 412 based on whether a composite mode is applied and whether block-level weight predictions are applicable to the composite mode. In some embodiments, the target weight factor list 412T is selected from a plurality of weight factor lists 412 based on whether a motion mode is applied and whether block-level weight predictions are applicable to the motion mode. In some embodiments, the target weight factor list 412T is selected from a plurality of weight factor lists 412 based on the JMVD scaling index and whether block-level weight predictions are applicable to the JMVD mode.

[0089] In some embodiments, the target weight factor list 412T is selected from a plurality of weight factor lists 412 based on the orientation of two reference image frames 406 and an MVP index that identifies the MVP of the MVP list for the current coding block 404.

[0090] In some embodiments, according to the determination that the orientations of two reference image frames 406A and 406B are different, the decoder 122 selects a target weight factor list 412T from a first set of positive weight factor lists (e.g., including 412A and 412D). All weight factors in each positive weight factor list are positive. Furthermore, in some embodiments, the MVP index associated with the MVP list is applied to select the target weight factor list 412T. For example, the decoder 122 selects the first weight factor list 412A as the target weight factor list 412T depending on the determination that the MVP index is even. Alternatively, the decoder 122 selects the fourth weight factor list 412D as the target weight factor list 412T depending on the determination that the MVP index is odd.

[0091] Alternatively, based on the determination that the orientation of the two reference image frames 406A and 406B is the same, the decoder 122 selects the target weight factor list 412T from a second set of mixed weight factor lists (e.g., including 412B and 412C) that is different from the first set of positive weight factor lists. Each mixed weight factor list contains at least one positive weight factor and at least one negative weight factor. Furthermore, in some embodiments, the MVP index associated with the MVP list is applied to select the target weight factor list 412T. For example, the decoder 122 selects the second weight factor list 412B as the target weight factor list 412T based on the determination that the MVP index is even. Alternatively, the decoder 122 selects the third weight factor list 412C as the target weight factor list 412T based on the determination that the MVP index is odd.

[0092] In some embodiments, the length of the weight factor list is the same among all supported weight factor lists of multiple weight factor lists 412.

[0093] In some embodiments, the multiple weight factor lists 412 correspond to a first subset of common weight factors (also called equal weight factors) used by all supported weight factor lists. In some embodiments, each weight factor list 412 contains at least one unequal weight factor that is not included in at least one of the remaining weight factor lists of each weight factor list 412. In some embodiments, one of the multiple weight factor lists 412 contains a subset of common weight factors but does not contain any unequal weight factors. Each of the remaining weight factor lists of the multiple weight factor lists 412 contains at least one unequal weight factor.

[0094] In some embodiments, the target weight factor list 412T is selected according to a determination of whether the index of the MVP in the MVP list is even or odd. For example, if the orientation of two reference image frames is different, two positive weight factor lists 412A and 412D are supported. One positive weight factor list 412A is {8,12,4} and the other positive weight factor list 412D is {8,10,6}. The first positive weight factor list 412A is used if the index of the MVP in the MVP list is even. Otherwise, the second positive weight factor list 412D is adopted.

[0095] Figure 6 shows several logical stages in a specific order, but the order-independent stages may be rearranged, and the other stages may be combined or separated. Several rearrangements or other groupings not specifically mentioned will be obvious to those skilled in the art, and therefore the rearrangements and groupings presented herein are not exhaustive. Furthermore, it should be noted that the stages may be implemented in hardware, firmware, software, or any combination thereof.

[0096] Here, we refer to some exemplary embodiments.

[0097] (A1) In one embodiment, several embodiments include a method 600 that is performed (for example by the decoding module 322 in Figure 3) to process video data. Method 600 includes the steps of receiving a video bitstream containing the current coding block of the current image frame (602) and determining that the current coding block should be predicted in WBP mode (604). In response to the current coding block being predicted in WBP mode (606), the method further includes the steps of determining that the current coding block is associated with two dual prediction blocks containing a first prediction block and a second prediction block (608) and identifying a plurality of distinct weight factor lists containing at least a first list and a second list (610). The first list has all positive weight factors. The second list has a mixed weight factor containing at least one positive weight factor and at least one negative weight factor, and the first list has at least one weight factor different from each of the weight factors in the second list. The method further includes the step of selecting one of a plurality of weight factor lists based on predetermined criteria (612) and the step of identifying a first weight factor from the selected one of the plurality of weight factor lists (614). The method further includes the step of reconstructing the current image frame (616), which includes the step of determining the current coding block by combining a first prediction block and a second prediction block based on the first weight factor (618).

[0098] (A2) In some embodiments of A1, the method 600 further includes the steps of associating a first weight factor with a first prediction block and determining a second weight factor of a second prediction block based on the first weight factor of the first prediction block. The first and second prediction blocks are then joined using the first and second weight factors, respectively.

[0099] (A3) In some embodiments of A2, the sum of the first weight factor and the second weight factor is equal to 1.

[0100] (A4) In some embodiments of A1 to A3, the step of selecting one of a plurality of weight factor lists based on predetermined criteria further includes the step of selecting a first list of positive weight factors in accordance with the determination that the first prediction block and the second prediction block have different orientations with respect to the current image frame.

[0101] (A5) In some embodiments of A1 to A3, the step of selecting one of a plurality of weight factor lists based on predetermined criteria further includes the step of selecting one of a plurality of weight factor lists based on predetermined criteria based on the predicted distance of the first predicted block, in accordance with the determination that the first predicted block and the second predicted block have the same orientation with respect to the current image frame.

[0102] (A6) In some embodiments of A5, the prediction distance is measured between (1) a first reference image frame containing a first prediction block and the current image frame, or (2) between the first reference image frame and a second reference image frame containing a second prediction block.

[0103] (A7) In some embodiments of A5 or A6, the list of weight factors further includes a third list of mixed weight factors having more negative weight factors than the second list of mixed weight factors. The step of selecting one of the list of weight factors based on a predetermined criterion further includes one of the steps of selecting a second list of mixed weight factors according to a determination that the predicted distance is less than a threshold distance, and selecting a third list of mixed weight factors according to a determination that the predicted distance is greater than or equal to a threshold distance.

[0104] (A8) In some embodiments of A1 to A3, the plurality of weight factor lists further include one or more third lists of mixed weight factors, each having one or more negative weight factors. The step of selecting one of the plurality of weight factor lists based on a predetermined criterion further includes the step of selecting one of the second and third lists of mixed weight factors based on a list indicator of syntax signaled in the current image frame, according to the determination that the first and second prediction blocks have the same orientation with respect to the current image frame.

[0105] (A9) In some embodiments of A1 to A3, the plurality of weight factor lists further include one or more third lists of mixed weight factors, each having one or more negative weight factors. The step of selecting one of the plurality of weight factor lists based on predetermined criteria further includes selecting one of the second and third lists of mixed weight factors based on the parity of the MVP index, in accordance with the determination that the first and second prediction blocks have the same orientation with respect to the current image frame, and selecting the MVP of the first narrative block from a predetermined MVP list.

[0106] In some embodiments of (A10)A9, the list of weight factors further includes a third list of mixed weight factors having one or more negative weight factors. The step of selecting one of the list of weight factors based on a predetermined criterion further includes one of the steps of selecting one of the second and third lists of mixed weight factors according to the determination that the MVP index is odd, and selecting the other of the second and third lists of mixed weight factors according to the determination that the MVP index is even.

[0107] (A11) In some embodiments of A1 to A10, the first list of positive weight factors has a first number of positive weight factors, and the second list of mixed weight factors has a second number of weight factors, where the first number is equal to the second number. For example, the first list of positive weight factors is {8,12,4,10,6,14,2} and the second list of mixed weight factors is {8,12,4,18,-2,20,-4}. In another example, the first list of positive weight factors is {8,12,4,10,6} and the second list of mixed weight factors is {8,12,4,20,-4}. In yet another example, the first list of positive weight factors is {8,12,4,10,6} and the second list of mixed weight factors is {8,10,6,20,-4}.

[0108] (A12) In some embodiments of A1 to A11, the multiple separate weight factor lists correspond to a set of common weight factors contained in each of the multiple separate weight factor lists. Each of the multiple separate weight factor lists further contains its own set of unique weight factors. Each unique weight factor is not contained in at least one of the multiple separate weight factor lists.

[0109] (A13) In some embodiments of A1 to A4 and A11 to A12, the step of selecting one of a plurality of weight factor lists based on predetermined criteria further includes the step of selecting one of a plurality of weight factor lists based on predetermined criteria based on the predicted distance of the first predicted block, in accordance with the determination that the first predicted block and the second predicted block have different orientations with respect to the current image frame.

[0110] (A14) In some embodiments of A13, the prediction distance is measured between (1) a first reference image frame containing a first prediction block and the current image frame, or (2) between the first reference image frame and a second reference image frame containing a second prediction block.

[0111] (A15) In some embodiments of A13 or A14, the list of weight factors further includes a fourth list of positive weight factors having more weight factors than the first list of positive weight factors. The step of selecting one of the list of weight factors based on a predetermined criterion further includes one of the steps of selecting a first list of positive weight factors according to the determination that the predicted distance is less than a threshold distance, and selecting a fourth list of positive weight factors according to the determination that the predicted distance is greater than or equal to a threshold distance.

[0112] (A16) In some embodiments of A1, the list of weight factors further includes one or a fourth list of positive weight factors. The step of selecting one of the list of weight factors based on a predetermined criterion further includes the step of selecting one of the first and fourth lists of positive weight factors based on a list indicator of syntax signaled in the current image frame, according to the determination that the first and second prediction blocks have different orientations with respect to the current image frame.

[0113] (A17) In some embodiments of A1-A4 and A11-A12, the plurality of weight factor lists further include one or more fourth lists of positive weight factors. The step of selecting one of the plurality of weight factor lists based on a predetermined criterion further includes selecting one of the first and fourth lists of positive weight factors based on the parity of the MVP index, selecting the MVP of the first narrative block from a predetermined MVP list according to the determination that the first and second prediction blocks have different orientations with respect to the current image frame.

[0114] (A18) In some embodiments of A1-A4 and A11-A12, the list of weight factors further includes a fourth list of positive weight factors. The step of selecting one of the first and fourth lists of positive weight factors further includes one of the steps of selecting one of the first and fourth lists of positive weight factors according to the determination that the MVP index is odd, and selecting the other of the first and fourth lists of positive weight factors according to the determination that the MVP index is even.

[0115] (A19) In other embodiments, some embodiments include a method 600 that is performed (for example by the encoding module 340 in Figure 3) to process video data. The method 600 includes the step of determining that the current coding block of the current image frame should be encoded in WBP mode. The method further includes, in response that the current coding block should be encoded in WBP mode, determining that the current coding block is associated with two dual prediction blocks, including a first prediction block and a second prediction block, and identifying a plurality of separate weight factor lists, including a first list of at least positive weight factors and a second list of mixed weight factors. The second list has at least one negative weight factor, and the first list has at least one weight factor different from each of the weight factors in the second list. The method further includes the step of selecting one of the plurality of weight factor lists based on a predetermined criterion, identifying a first weight factor from the selected one of the plurality of weight factor lists, and estimating the current coding block by combining the first prediction block and the second prediction block based on the first weight factor. The method further includes the step of generating a video bitstream containing the current coding block of the current image frame.

[0116] In other embodiments, some embodiments include a computing system (e.g., server system 112) which includes a control circuit (e.g., control circuit 302) and a memory coupled to the control circuit (e.g., memory 314), the memory which stores one or more instruction sets configured to be executed by the control circuit, the one or more instruction sets which include instructions for performing any of the methods described herein (e.g., A1 to A19 above).

[0117] In further embodiments, some embodiments include a non-temporary computer-readable storage medium that stores one or more instruction sets for execution by a control circuit of a computing system, the one or more instruction sets including instructions for doing any of the methods described herein (e.g., A1 to A19 above).

[0118] The proposed methods may be used separately or combined in any order. Furthermore, each of the methods (or embodiments), encoders, and decoders may be implemented by processing circuits (e.g., one or more processors or one or more integrated circuits). For example, one or more processors execute a program stored in a non-temporary computer-readable medium. Hereinafter, the term "block" may be interpreted as a prediction block, coding block, or coding unit, i.e., a CU.

[0119] Terms such as "first," "second," etc., may be used herein to describe various elements, but it should be understood that these elements should not be limited by these terms. These terms are used solely to distinguish one element from another.

[0120] The terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the scope of the claims. As used in the descriptions of embodiments and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural form unless the context clearly indicates otherwise. The terms “and / or” as used herein will be understood to refer to and include one or any possible combination of the enumerated items relating to the description. The terms “comprises” and / or “comprising,” as used herein, identify the presence of the described features, integers, steps, actions, elements, and / or components, but are not intended to exclude the presence or addition of one or more other features, integers, steps, actions, elements, components, and / or groups thereof.

[0121] As used herein, the term “if” can be interpreted, depending on the context, to mean “when” or “upon” or “in response to determining” or “in accordance with a determination” or “in response to detecting” that the stated premise is true. Similarly, the phrases “if it is determined that [the stated premise is true]” or “when [the stated premise is true]” or “when [the stated premise is true]” can be interpreted, depending on the context, to mean “upon determining” or “in response to determining” or “in accordance with a determination” or “upon detecting” or “in response to detecting” that the stated premise is true.

[0122] The above description is based on reference to specific embodiments for illustrative purposes. However, the above exemplary description is not intended to be exhaustive or to limit the claims to the exact form disclosed. Many modifications and variations are possible in light of the above teachings. The embodiments have been selected and described to best illustrate the operating principle and practical applications, and thereby to be available to those skilled in the art. [Explanation of symbols]

[0123] 100 Communication system, 102 Source device, 104 Video source, 106 Encoder, Encoder components, 108 Video bitstream, 110 Network, 112 Server system, 114 Coder components, 116 Video data, 120 Electronic device, 122 Decoder, Decoder components, 124 Display, 202 Source coder, 204 Controller, 206 Predictor, 208 Reference picture memory, 210 Decoder, Local decoder, 212 Coding engine, 214 Entropy coder, 216 Video sequence, 218 Channel, Communication channel, 252 Buffer memory, 254 Parser, 256 Loop filter, Loop filter unit, 258 Inverse transform unit, 260 Motion compensation prediction unit, 262 Intra picture prediction unit, 264 Current picture memory, 266 Reference picture memory, 268 Aggregator, 270 Symbol, 302 Control circuit, 304 Network interface, 306 User interface, 308 Output device, 310 Input device, 312 Communication bus, 314 Memory, 316 Operating system, 318 Network communication module, 320 Coding module, 322 Decoding module, 324 Parsing module, 326 Transform module, 328 Prediction module, 330 Filter module, 340 Encoding module, 342 Code module, 344 Prediction module, 352 Picture memory, 402 Current coding block, current image frame, 404 Current image frame, current coding block, 406 Reference image, reference image frame, first reference image frame, 406A Reference image frame, first reference image, first reference image frame, 406B Second reference image, second reference image frame, 408 Prediction block, 408A Reference prediction block, first prediction block, prediction block, 408B Second prediction block, 412 Weight factor list, first list, 412A First list of positive weight factors, first weight factor list, 412B Second list of mixed weight factors, weight factor, weight factor list, second list, second weight factor list, 412COne or more third lists of mixed weight factors, third list, 412D weight factor list, one or more fourth lists of positive weight factors, fourth list, fourth weight factor list, 412T target weight factor list, 414 first weight factor, 416 second weight factor, 420 criteria, 500 dual prediction scheme, 600 method

Claims

1. A method for decoding video data, The steps include receiving a video bitstream containing the current coding block of the current image frame, The steps include determining that the current coding block should be predicted in weighted biprediction (WBP) mode, In response to the current coding block being predicted in the WBP mode, The steps include determining that the current coding block is associated with two dual prediction blocks, including a first prediction block and a second prediction block, A step of identifying a plurality of distinct weight factor lists, each including at least a first list and a second list, wherein all of the first list lists have positive weight factors, each of the second list lists has at least one negative weight factor, and each of the first list lists has at least one weight factor different from each of the weight factors in the second list. A step of selecting one of the multiple weight factor lists based on predetermined criteria, The steps include identifying a first weight factor from the selected one among the plurality of weight factor lists, The steps include: reconstructing the current image frame, which includes determining the current coding block by combining the first prediction block and the second prediction block based on the first weighting factor; Methods that include...

2. The steps include associating the first weighting factor with the first prediction block, A step of determining the second weight factor of the second prediction block based on the first weight factor of the first prediction block. It further includes, The first prediction block and the second prediction block are combined using the first weight factor and the second weight factor, respectively. The method according to claim 1.

3. The method according to claim 2, wherein the sum of the first weighting factor and the second weighting factor is equal to 1.

4. The step of selecting one of the plurality of weight factor lists based on the predetermined criteria is: Steps to select the first list of positive weighting factors in accordance with the determination that the first prediction block and the second prediction block have different orientations with respect to the current image frame. The method according to claim 1, further comprising:

5. The step of selecting one of the plurality of weight factor lists based on the predetermined criteria is: Step 1: Select one of the plurality of weight factor lists based on the predicted distance of the first predicted block, in accordance with the determination that the first predicted block and the second predicted block have the same orientation with respect to the current image frame. The method according to claim 1, further comprising:

6. The method according to claim 5, wherein the predicted distance is measured between (1) a first reference image frame containing the first prediction block and the current image frame, or (2) between the first reference image frame and a second reference image frame containing the second prediction block.

7. The plurality of weight factor lists further include a third list of mixed weight factors having more negative weight factors than a second list of mixed weight factors, and the step of selecting one of the plurality of weight factor lists based on the predetermined criteria is, The steps include selecting a second list of the mixed weight factors in accordance with the determination that the predicted distance is less than the threshold distance, and The step of selecting a third list of the mixed weighting factors in accordance with the determination that the predicted distance is greater than or equal to the threshold distance. The method according to claim 5, further comprising one of the following.

8. The plurality of weight factor lists further include one or a third list of mixed weight factors, each having one or a few negative weight factors, and the step of selecting one of the plurality of weight factor lists based on the predetermined criteria is: Steps to select one of the second and third lists of the mixed weight factors based on a list indicator of syntax signaled in the current image frame, in accordance with the determination that the first and second prediction blocks have the same orientation with respect to the current image frame. The method according to claim 1, further comprising:

9. The plurality of weight factor lists further include one or a third list of mixed weight factors, each having one or a few negative weight factors, and the step of selecting one of the plurality of weight factor lists based on the predetermined criteria is: Steps to select one of the second and third lists of mixed weight factors based on the parity of the MVP index, in accordance with the determination that the first and second prediction blocks have the same orientation with respect to the current image frame, and selecting the MVP of the first description block from a predetermined motion vector predictor (MVP) list. The method according to claim 1, further comprising:

10. The plurality of weight factor lists further include a third list of mixed weight factors having one or more negative weight factors, and the step of selecting one of the plurality of weight factor lists based on predetermined criteria is, The steps include selecting one of the second and third lists of the mixed weight factors in accordance with the determination that the MVP index is odd, and The step of selecting the other of the second and third lists of the mixed weight factors, in accordance with the determination that the MVP index is even. The method according to claim 9, further comprising one of the following.

11. A computing system, Control circuit, and A memory for storing one or more programs configured to be executed by the control circuit, wherein the one or more programs are To receive a video bitstream containing the current coding block of the current image frame, Determine that the current coding block should be predicted in weighted biprediction (WBP) mode. In response to the current coding block being predicted in the WBP mode, It is determined that the current coding block is associated with two dual prediction blocks, including a first prediction block and a second prediction block. Identifying a plurality of distinct weight factor lists, each including at least a first list and a second list, wherein all of the first list have positive weight factors, each of the second list has at least one negative weight factor, and each of the first list has at least one weight factor different from each of the weight factors in the second list. Based on predetermined criteria, select one of the above list of weight factors, Identify a first weight factor from the selected one among the plurality of weight factor lists, Reconstructing the current image frame, including determining the current coding block by combining the first prediction block and the second prediction block based on the first weighting factor. Further instructions for memory A computing system equipped with [the following features].

12. The computing system according to claim 11, wherein the first list of positive weight factors has a first number of positive weight factors, and the second list of mixed weight factors has a second number of weight factors, and the first number is equal to the second number.

13. The aforementioned list of separate weight factors corresponds to a set of common weight factors included in each of the aforementioned list of separate weight factors, Each of the aforementioned separate lists of weight factors further includes its own set of weight factors, Each unique weight factor is not included in at least one of the aforementioned list of separate weight factors. The computing system according to claim 11.

14. Selecting one of the multiple weight factor lists based on the predetermined criteria is: In accordance with the determination that the first and second prediction blocks have different orientations with respect to the current image frame, one of the plurality of weight factor lists is selected based on the predicted distance of the first prediction block. The computing system according to claim 11, further comprising:

15. The computing system according to claim 14, wherein the predicted distance is measured between (1) a first reference image frame containing the first prediction block and the current image frame, or (2) between the first reference image frame and a second reference image frame containing the second prediction block.

16. The plurality of weight factor lists further include a fourth list of positive weight factors having more weight factors than the first list of positive weight factors, and selecting one of the plurality of weight factor lists based on the predetermined criteria, In accordance with the determination that the predicted distance is less than the threshold distance, a first list of positive weighting factors is selected, and Select the fourth list of positive weighting factors in accordance with the determination that the predicted distance is greater than or equal to the threshold distance. The computing system according to claim 14, further comprising one of the following.

17. A non-temporary computer-readable storage medium for storing one or more programs to be executed by a control circuit of a computing system, wherein the one or more programs are To receive a video bitstream containing the current coding block of the current image frame, Determine that the current coding block should be predicted in weighted biprediction (WBP) mode. In response to the current coding block being predicted in the WBP mode, It is determined that the current coding block is associated with two dual prediction blocks, including a first prediction block and a second prediction block. Identifying a plurality of distinct weight factor lists, each including at least a first list and a second list, wherein all of the first list have positive weight factors, each of the second list has at least one negative weight factor, and each of the first list has at least one weight factor different from each of the weight factors in the second list. Based on predetermined criteria, select one of the above list of weight factors, Identify a first weight factor from the selected one among the plurality of weight factor lists, Reconstructing the current image frame, including determining the current coding block by combining the first prediction block and the second prediction block based on the first weighting factor. A non-temporary computer-readable storage medium containing instructions for [a specific object / device].

18. The plurality of weight factor lists further include one or more fourth lists of positive weight factors, and selecting one of the plurality of weight factor lists based on the predetermined criteria is: In accordance with the determination that the first and second prediction blocks have different orientations with respect to the current image frame, one of the first and fourth lists of positive weighting factors is selected based on the list indicator of syntax signaled in the current image frame. A non-temporary computer-readable storage medium according to claim 17, further comprising:

19. The plurality of weight factor lists further include one or more fourth lists of positive weight factors, and selecting one of the plurality of weight factor lists based on the predetermined criteria is: In accordance with the determination that the first and second prediction blocks have different orientations with respect to the current image frame, one of the first and fourth lists of positive weight factors is selected from a predetermined motion vector predictor (MVP) list, based on the parity of the MVP index, to select the MVP of the first narrative block. A non-temporary computer-readable storage medium according to claim 17, further comprising:

20. The plurality of weight factor lists further include a fourth list of positive weight factors, and one of the first list and the fourth list of positive weight factors is selected based on the predetermined criteria. In accordance with the determination that the MVP index is odd, one of the first list and the fourth list of positive weight factors is selected, and In accordance with the determination that the MVP index is even, select the other of the first and fourth lists of positive weight factors. A non-temporary computer-readable storage medium according to claim 19, further comprising:

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