Intra prediction fusion for video coding

Abstract

A method of decoding video data includes generating a fusion of predictors from two or more sample reference rows relative to a block of video data based on an intra prediction mode. The method also includes decoding the block of video data using the fusion of the predictor and the intra prediction mode.

Description

[0001] This application claims priority to U.S. Patent Application No. 18 / 339,302, filed on June 22, 2023, U.S. Provisional Patent Application No. 63 / 367,804, filed on July 6, 2022, and U.S. Provisional Patent Application No. 63 / 368,221, filed on July 12, 2022, each of which is incorporated herein by reference in its entirety. U.S. Patent Application No. 18 / 339,302, filed on June 22, 2023, claims the benefit of U.S. Provisional Patent Application No. 63 / 367,804, filed on July 6, 2022, and the benefit of U.S. Provisional Patent Application No. 63 / 368,221, filed on July 12, 2022. Technical Field

[0002] The present disclosure relates to video encoding and video decoding. Background Art

[0003] Digital video capabilities may be incorporated into a variety of devices, including digital televisions, digital direct broadcast systems, wireless broadcast systems, personal digital assistants (PDAs), laptop or desktop computers, tablet computers, e-book readers, digital cameras, digital recording devices, digital media players, video game devices, video game consoles, cellular or satellite radio telephones, so-called "smart phones", video teleconferencing devices, video streaming devices, and the like. Digital video devices implement video coding techniques, such as those described in the standards defined by MPEG-2, MPEG-4, ITU-T H.263, ITU-T H.264 / MPEG-4, Part 10, Advanced Video Coding (AVC), ITU-T H.265 / High Efficiency Video Coding (HEVC), ITU-T H.266 / Versatile Video Coding (VVC), and extensions of such standards, as well as proprietary video codecs / formats such as AOMedia Video 1 (AV1) developed by the Alliance for Open Media. By implementing such video coding techniques, video devices may more efficiently send, receive, encode, decode, and / or store digital video information.

[0004] Video coding techniques include spatial (intra-picture) prediction and / or temporal (inter-picture) prediction to reduce or eliminate redundancy inherent in video sequences. For block-based video coding, a video slice (e.g., a video picture or a portion of a video picture) may be divided into video blocks, which may also be referred to as coding tree units (CTUs), coding units (CUs), and / or coding nodes. Video blocks in an intra-coded (I) slice of a picture are encoded using spatial prediction relative to reference samples in neighboring blocks in the same picture. Video blocks in an inter-coded (P or B) slice of a picture may use spatial prediction relative to reference samples in neighboring blocks in the same picture, or temporal prediction relative to reference samples in other reference pictures. Pictures may be referred to as frames, and reference pictures may be referred to as reference frames. Summary of the invention

[0005] In general, the present disclosure describes techniques for decoding video data. Specifically, the present disclosure describes techniques for decoding a block of video data using a fusion of predictors from two or more sample reference rows based on an intra-frame prediction mode. For example, a video decoder may combine (e.g., fuse) reference samples from two or more sample reference rows to form a new fusion of predictors, which may be used to decode video data according to an intra-frame prediction mode. By fusing predictors from two or more reference rows, a system may generate more accurate predictions. Thus, the techniques may reduce computing resources, which may be particularly important for resource-constrained devices such as smart phones, tablet computers, embedded systems, and the like. Additionally, the techniques may reduce the time required to decode and display video content, which may reduce latency (e.g., the delay between capturing a video frame and displaying a video frame), improve streaming performance, and the like. Thus, the techniques may improve the coding efficiency and performance of intra-frame predictions in a video codec.

[0006] In one example, a method includes generating a fusion of predictors from two or more sample reference rows relative to a block of video data based on an intra prediction mode; and decoding the block of video data using the fusion of predictors and the intra prediction mode.

[0007] In another example, a device includes a memory and one or more processors in communication with the memory, the one or more processors configured to: generate a fusion of predictors from two or more sample reference rows relative to a block of video data based on an intra-frame prediction mode; and decode the block of video data using the fusion of predictors and the intra-frame prediction mode.

[0008] In another example, an apparatus includes: means for generating a fusion of predictors from two or more sample reference rows relative to a block of video data based on an intra-frame prediction mode; and means for decoding the block of video data using the fusion of predictors and the intra-frame prediction mode.

[0009] In another example, a computer-readable storage medium is encoded with instructions that, when executed, cause a programmable processor to: generate a fusion of predictors from two or more sample reference rows relative to a block of video data based on an intra-frame prediction mode; and decode the block of video data using the fusion of predictors and the intra-frame prediction mode.

[0010] In another example, a method includes generating a fusion of predictors from two or more sample reference rows relative to a block of video data based on an intra prediction mode, and encoding the block of video data using the fusion of predictors and the intra prediction mode.

[0011] In another example, a device includes a memory and one or more processors in communication with the memory, the one or more processors configured to: generate a fusion of predictors from two or more sample reference rows relative to a block of video data based on an intra-frame prediction mode; and encode the block of video data using the fusion of predictors and the intra-frame prediction mode.

[0012] In another example, an apparatus includes: means for generating a fusion of predictors from two or more sample reference rows relative to a block of video data based on an intra-frame prediction mode; and means for encoding the block of video data using the fusion of predictors and the intra-frame prediction mode.

[0013] In another example, a computer-readable storage medium is encoded with instructions that, when executed, cause a programmable processor to: generate a fusion of predictors from two or more sample reference rows relative to a block of video data based on an intra-frame prediction mode; and encode the block of video data using the fusion of predictors and the intra-frame prediction mode.

[0014] The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a block diagram illustrating an example video encoding and decoding system that may perform the techniques of this disclosure.

[0016] Figure 2is a conceptual diagram illustrating example reference rows for intra prediction.

[0017] Figure 3 is a conceptual diagram illustrating an example of multiple reference lines used for intra prediction.

[0018] Figure 4 is a conceptual diagram showing example templates and reference samples used in template-based intra mode derivation (TIMD).

[0019] Figure 5 is a conceptual diagram illustrating an example angular intra prediction mode in one version of the Enhanced Compression Model (ECM).

[0020] Figure 6 is a conceptual diagram illustrating examples of integer slopes and non-integer slopes for angular intra prediction modes.

[0021] Figure 7 is a block diagram illustrating an example video encoder that may perform the techniques of this disclosure.

[0022] Figure 8 is a block diagram illustrating an example video decoder that may perform the techniques of this disclosure.

[0023] Fig. 9 is a flowchart illustrating an example method for encoding a current block according to techniques of this disclosure.

[0024] Fig.10 is a flow chart illustrating an example method for decoding a current block according to techniques of this disclosure.

[0025] Fig.11 is a flowchart illustrating an example method for encoding a current block according to techniques of this disclosure.

[0026] Fig.12 is a flow chart illustrating an example method for decoding a current block according to techniques of this disclosure. DETAILED DESCRIPTION

[0027] In general, video coding techniques can use intra-frame prediction to reduce the amount of data required to represent video content while maintaining high visual quality. Example intra-frame prediction modes may include DC mode, plane mode, and directional mode (e.g., angle mode). The selection of intra-frame prediction mode for a particular block may depend on the content within the block and adjacent blocks. Although intra-frame prediction provides several advantages in video compression, it also has some disadvantages. For example, intra-frame prediction may sometimes generate relatively large residual data (e.g., the difference between the predicted block and the actual block). Encoding large residual data can result in lower compression efficiency.

[0028] The present disclosure describes techniques that can improve the decoding efficiency of intra-frame prediction. Specifically, the present disclosure describes the following techniques: in these techniques, intra-frame prediction is performed by forming a fused reference predictor using two or more sample reference rows. That is, a video decoder can combine (e.g., fuse) reference samples from two or more sample reference rows to form a new fusion of predictors, which can be used to decode video data according to an intra-frame prediction mode. By fusing predictors from two or more reference rows, the system can generate more accurate predictions, which can not only result in smaller residual data that can be compressed more efficiently, but also improve visual quality (e.g., because more accurate block prediction algorithms reduce errors and artifacts introduced during the compression and decompression process). In addition, these techniques can result in faster decoding times and lower computational resource requirements, which may be particularly important for resource-constrained devices and applications (such as streaming).

[0029] Figure 1 1 is a block diagram illustrating an example video encoding and decoding system 100 that can perform the techniques of the present disclosure. The techniques of the present disclosure are generally directed to decoding (i.e., encoding and / or decoding) video data. Generally, video data includes any data used to process video. Thus, video data can include: original unencoded video, encoded video, decoded (e.g., reconstructed) video, and video metadata (e.g., signaling data).

[0030] like Figure 1 As shown, in this example, the system 100 includes a source device 102 that provides encoded video data to be decoded and displayed by a destination device 116. Specifically, the source device 102 provides the video data to the destination device 116 via a computer-readable medium 110. The source device 102 and the destination device 116 may include any of a variety of devices, including: a desktop computer, a notebook (i.e., laptop) computer, a mobile device, a tablet, a set-top box, a telephone handset (e.g., a smart phone), a television, a camera, a display device, a digital media player, a video game console, a video streaming device, a broadcast receiver device, etc. In some cases, the source device 102 and the destination device 116 may be equipped for wireless communication and may therefore be referred to as wireless communication devices.

[0031] exist Figure 1In the example of , the source device 102 includes a video source 104, a memory 106, a video encoder 200, and an output interface 108. The destination device 116 includes an input interface 122, a video decoder 300, a memory 120, and a display device 118. According to the present disclosure, the video encoder 200 of the source device 102 and the video decoder 300 of the destination device 116 can be configured to apply a technique for intra-frame prediction fusion. Therefore, the source device 102 represents an example of a video encoding device, and the destination device 116 represents an example of a video decoding device. In other examples, the source device and the destination device may include other components or arrangements. For example, the source device 102 may receive video data from an external video source such as an external camera. Similarly, the destination device 116 may be connected to an external display device with an interface, rather than including an integrated display device.

[0032] like Figure 1 The system 100 shown is only an example. In general, any digital video encoding and / or decoding device can perform techniques for intra-frame prediction fusion. The source device 102 and the destination device 116 are only examples of such decoding devices, wherein the source device 102 generates decoded video data for transmission to the destination device 116. The present disclosure refers to a "decoding" device as a device that performs decoding (encoding and / or decoding) of data. Therefore, the video encoder 200 and the video decoder 300 represent examples of decoding devices, specifically video encoders and video decoders, respectively. In some examples, the source device 102 and the destination device 116 can operate in a substantially symmetrical manner, so that each device in the source device 102 and the destination device 116 includes a video encoding and decoding component. Therefore, the system 100 can support one-way or two-way video transmission between the source device 102 and the destination device 116, for example, for video streaming, video playback, video broadcasting, or video telephony.

[0033] Typically, the video source 104 represents a source of video data (i.e., original, uncoded video data), and provides a sequence of pictures (also referred to as "frames") of the video data to the video encoder 200, which encodes the data of the pictures. The video source 104 of the source device 102 may include a video capture device, such as a camera, a video archive containing previously captured original video, and / or a video feed interface for receiving video from a video content provider. As another alternative, the video source 104 may generate computer graphics-based data as the source video, or a combination of real-time video, archived video, and computer-generated video. In each case, the video encoder 200 encodes the captured, pre-captured, or computer-generated video data. The video encoder 200 may rearrange the pictures from the receiving order (sometimes referred to as the "display order") to the decoding order for decoding. The video encoder 200 may generate a bitstream including the encoded video data. Source device 102 may then output the encoded video data onto computer-readable medium 110 via output interface 108 for receipt and / or retrieval by, for example, input interface 122 of destination device 116 .

[0034] The memory 106 of the source device 102 and the memory 120 of the destination device 116 represent general purpose memory. In some examples, the memories 106, 120 can store original video data, for example, original video from the video source 104 and original decoded video data from the video decoder 300. In addition or alternatively, the memories 106, 120 can store software instructions that can be executed by, for example, the video encoder 200 and the video decoder 300, respectively. Although the memory 106 and the memory 120 are shown separately from the video encoder 200 and the video decoder 300 in this example, it should be understood that the video encoder 200 and the video decoder 300 can also include internal memory to achieve functionally similar or equivalent purposes. In addition, the memories 106, 120 can store, for example, encoded video data output from the video encoder 200 and input to the video decoder 300. In some examples, portions of the memories 106, 120 can be allocated as one or more video buffers, for example, to store original video data, decoded video data, and / or encoded video data.

[0035] The computer-readable medium 110 may represent any type of medium or device capable of transmitting the encoded video data from the source device 102 to the destination device 116. In one example, the computer-readable medium 110 represents a communication medium for enabling the source device 102 to send the encoded video data directly to the destination device 116 in real time (e.g., via a radio frequency network or a computer-based network). According to a communication standard such as a wireless communication protocol, the output interface 108 may modulate a transmission signal including the encoded video data, and the input interface 122 may demodulate the received transmission signal. The communication medium may include any wireless or wired communication medium, such as a radio frequency (RF) spectrum or one or more physical transmission lines. The communication medium may form a portion of a packet-based network such as a local area network, a wide area network, or a global network such as the Internet. The communication medium may include a router, a switch, a base station, or any other device that can be used to facilitate communication from the source device 102 to the destination device 116.

[0036] In some examples, source device 102 may output the encoded data from output interface 108 to storage device 112. Similarly, destination device 116 may access the encoded data from storage device 112 via input interface 122. Storage device 116 may include any of a variety of distributed or locally accessed data storage media, such as a hard drive, Blu-ray disc, DVD, CD-ROM, flash memory, volatile or non-volatile memory, or any other suitable digital storage medium for storing encoded video data.

[0037] In some examples, source device 102 may output the encoded video data to file server 114 or another intermediate storage device, which may store the encoded video data generated by source device 102. Destination device 116 may access the stored video data from file server 114 via streaming or downloading.

[0038] The file server 114 may be any type of server device capable of storing encoded video data and sending the encoded video data to the destination device 116. The file server 114 may represent a website server (e.g., for a website), a server configured to provide file transfer protocol services (such as the File Transfer Protocol (FTP) or the File Delivery over Unidirectional Transport (FLUTE) protocol), a content delivery network (CDN) device, a hypertext transfer protocol (HTTP) server, a Multimedia Broadcast Multicast Service (MBMS) or enhanced MBMS (eMBMS) server, and / or a network attached storage (NAS) device. The file server 114 may additionally or alternatively implement one or more HTTP streaming protocols, such as Dynamic Adaptive Streaming over HTTP (DASH), HTTP Live Streaming (HLS), Real-Time Streaming Protocol (RTSP), HTTP Dynamic Streaming, and the like.

[0039] Destination device 116 may access the encoded video data from file server 114 through any standard data connection, including an Internet connection. This may include a wireless channel (e.g., a Wi-Fi connection), a wired connection (e.g., a digital subscriber line (DSL), a cable modem, etc.), or a combination of both, suitable for accessing the encoded video data stored on file server 114. Input interface 122 may be configured to operate according to any one or more of the various protocols discussed above for retrieving or receiving media data from file server 114, or other such protocols for retrieving media data.

[0040] Output interface 108 and input interface 122 may represent wireless transmitters / receivers, modems, wired networking components (e.g., Ethernet cards), wireless communication components that operate according to any of the various IEEE 802.11 standards, or other physical components. In examples where output interface 108 and input interface 122 include wireless components, output interface 108 and input interface 122 may be configured to forward data such as encoded video data according to cellular communication standards such as 4G, 4G-LTE (Long Term Evolution), LTE Advanced, 5G, etc. In some examples where output interface 108 includes a wireless transmitter, output interface 108 and input interface 122 may be configured to forward data such as encoded video data according to other wireless standards such as IEEE 802.11 specifications, IEEE 802.15 specifications (e.g., ZigBee 5G, etc.). TM ),Bluetooth TMStandards, etc.) to forward data such as encoded video data. In some examples, source device 102 and / or destination device 116 may include respective system-on-chip (SoC) devices. For example, source device 102 may include an SoC device to perform functions belonging to video encoder 200 and / or output interface 108, and destination device 116 may include an SoC device to perform functions belonging to video decoder 300 and / or input interface 122.

[0041] The techniques of the present disclosure may be applied to video decoding to support any of a variety of multimedia applications, such as over-the-air television broadcasts, cable television transmissions, satellite television transmissions, Internet streaming video transmissions (e.g., Dynamic Adaptive Streaming over HTTP (DASH)), digital video encoded onto a data storage medium, decoding of digital video stored on a data storage medium, or other applications.

[0042] The input interface 122 of the destination device 116 receives an encoded video bitstream from the computer-readable medium 110 (e.g., a communication medium, a storage device 112, a file server 114, etc.). The encoded video bitstream may include signaling information defined by the video encoder 200, which is also used by the video decoder 300, such as syntax elements with values ​​describing characteristics and / or processing of video blocks or other decoding units (e.g., slices, pictures, groups of pictures, sequences, etc.). The display device 118 displays decoded pictures of the decoded video data to a user. The display device 118 may represent any of a variety of display devices, such as a liquid crystal display (LCD), a plasma display, an organic light emitting diode (OLED) display, or another type of display device.

[0043] Although not in Figure 1 , but in some examples, the video encoder 200 and the video decoder 300 may each be integrated with an audio encoder and / or an audio decoder, and may include appropriate MUX-DEMUX units or other hardware and / or software to process a multiplexed stream including both audio and video in a common data stream.

[0044] The video encoder 200 and the video decoder 300 can each be implemented as any of a variety of suitable encoder and / or decoder circuits, such as one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), discrete logic circuits, software, hardware, firmware, or any combination thereof. When the technology is partially implemented in software, the device may store instructions for the software in a suitable non-transitory computer-readable medium and use one or more processors to execute the instructions in hardware to perform the technology of the present disclosure. Each of the video encoder 200 and the video decoder 300 can be included in one or more encoders or decoders, any of which can be integrated as part of a combined encoder / decoder (CODEC) in a corresponding device. The device including the video encoder 200 and / or the video decoder 300 may include an integrated circuit, a microprocessor, and / or a wireless communication device, such as a cellular phone.

[0045] The video encoder 200 and the video decoder 300 may operate according to a video coding standard such as ITU-T H.265, also known as High Efficiency Video Coding (HEVC) or an extension thereof, such as multi-view and / or scalable video coding extension. Alternatively, the video encoder 200 and the video decoder 300 may operate according to other proprietary or industry standards such as ITU-T H.266, also known as Versatile Video Coding (VVC). In other examples, the video encoder 200 and the video decoder 300 may operate according to a proprietary video codec / format such as AOMedia Video 1 (AV1), an extension of AV1, and / or a subsequent version of AV1 (e.g., AV2). In other examples, the video encoder 200 and the video decoder 300 may operate according to other proprietary formats or industry standards. However, the technology of the present disclosure is not limited to any particular coding standard or format. In general, the video encoder 200 and the video decoder 300 may be configured to perform the technology of the present disclosure in conjunction with any video coding technology that uses intra-frame prediction.

[0046] Typically, the video encoder 200 and the video decoder 300 can perform block-based decoding of the picture. The term "block" generally refers to a structure that includes data to be processed (e.g., encoded, decoded, or otherwise used in the encoding and / or decoding process). For example, a block may include a two-dimensional matrix of samples of luminance and / or chrominance data. Typically, the video encoder 200 and the video decoder 300 can decode video data represented in a YUV (e.g., Y, Cb, Cr) format. That is, instead of decoding the red, green, and blue (RGB) data of the samples of the picture, the video encoder 200 and the video decoder 300 can decode the luminance component and the chrominance component, wherein the chrominance component may include both a red-tone component and a blue-tone chrominance component. In some examples, the video encoder 200 converts the received RGB format data into a YUV representation before encoding, and the video decoder 300 converts the YUV representation into an RGB format. Alternatively, a pre-processing unit and a post-processing unit (not shown) can perform these conversions.

[0047] The present disclosure may generally relate to the decoding (e.g., encoding and decoding) of a picture to include the process of encoding or decoding the data of the picture. Similarly, the present disclosure may relate to the decoding of a block of a picture to include the process of encoding or decoding the data of the block, for example, prediction and / or residual decoding. The encoded video bitstream typically includes a series of values ​​for syntax elements that represent decoding decisions (e.g., decoding modes) and the partitioning of the picture into blocks. Therefore, references to decoding a picture or a block should generally be understood as decoding the values ​​of the syntax elements used to form the picture or the block.

[0048] HEVC defines various blocks, including coding units (CUs), prediction units (PUs), and transform units (TUs). According to HEVC, a video decoder (e.g., video encoder 200) divides a coding tree unit (CTU) into CUs according to a quadtree structure. That is, the video decoder divides the CTU and CU into four equal non-overlapping squares, and each node of the quadtree has zero or four child nodes. A node without child nodes may be referred to as a "leaf node", and the CU of such a leaf node may include one or more PUs and / or one or more TUs. The video decoder may further divide the PU and TU. For example, in HEVC, a residual quadtree (RQT) represents the division of a TU. In HEVC, a PU represents inter-frame prediction data, and a TU represents residual data. An intra-predicted CU includes intra-frame prediction information, such as an intra-frame mode indication.

[0049] As another example, the video encoder 200 and the video decoder 300 may be configured to operate according to VVC. According to VVC, a video decoder (such as the video encoder 200) divides a picture into a plurality of coding tree units (CTUs). The video encoder 200 may divide the CTU according to a tree structure such as a quadtree-binary tree (QTBT) structure or a multi-type tree (MTT) structure. The QTBT structure eliminates the concept of multiple partition types, such as the separation between CU, PU, ​​and TU of HEVC. The QTBT structure includes two levels: a first level divided according to quadtree partitioning, and a second level divided according to binary tree partitioning. The root node of the QTBT structure corresponds to the CTU. The leaf nodes of the binary tree correspond to the coding units (CUs).

[0050] In the MTT partition structure, blocks can be partitioned using quadtree (QT) partitioning, binary tree (BT) partitioning, and one or more types of ternary tree (TT) (also known as ternary tree (TT)) partitioning. A ternary tree or ternary tree partition is a partition that divides a block into three sub-blocks. In some examples, the ternary tree or ternary tree partition divides the block into three sub-blocks without dividing the original block via the center. The partition types in MTT (e.g., QT, BT, and TT) can be symmetric or asymmetric.

[0051] When operating according to the AV1 codec, the video encoder 200 and the video decoder 300 may be configured to decode the video data in the block. In AV1, the largest decoding block that can be processed is called a super block. In AV1, a super block may be 128×128 luma samples or 64×64 luma samples. However, in subsequent video coding formats (e.g., AV2), super blocks may be defined by different (e.g., larger) luma sample sizes. In some examples, the super block is the top level of the block quadtree. The video encoder 200 may further divide the super block into smaller decoding blocks. The video encoder 200 may divide the super block and other decoding blocks into smaller blocks using square or non-square partitioning. Non-square blocks may include N / 2×N, N×N / 2, N / 4×N, and N×N / 4 blocks. The video encoder 200 and the video decoder 300 may perform separate prediction and transform processing on each decoding block.

[0052] AV1 also defines tiles of video data. A tile is a rectangular array of super blocks that can be decoded independently of other tiles. That is, the video encoder 200 and the video decoder 300 can encode and decode coded blocks within a tile, respectively, without using video data from other tiles. However, the video encoder 200 and the video decoder 300 can perform filtering across tile boundaries. The size of the tiles can be uniform or non-uniform. Tile-based decoding can enable parallel processing and / or multi-threading for encoder and decoder implementations.

[0053] In some examples, the video encoder 200 and the video decoder 300 may use a single QTBT or MTT structure to represent each of the luma components and the chroma components, while in other examples, the video encoder 200 and the video decoder 300 may use two or more QTBT or MTT structures, such as one QTBT / MTT structure for the luma component and another QTBT / MTT structure for the two chroma components (or two QTBT / MTT structures for the corresponding chroma components).

[0054] The video encoder 200 and the video decoder 300 may be configured to use quadtree partitioning, QTBT partitioning, MTT partitioning, super block partitioning, or other partitioning structures.

[0055] In some examples, a CTU includes: a coding tree block (CTB) of luma samples of a picture having three sample arrays, two corresponding CTBs of chroma samples, or a CTB of samples of a monochrome picture or a picture coded using three separate color planes; and a syntax structure for coding the samples. A CTB can be an N×N block of samples for some value of N, so that the division of components into CTBs is a "partition". A component is an array or a single sample from one of the three arrays (luminance and two chroma) that make up a picture of 4:2:0, 4:2:2, or 4:4:4 color format, or an array or a single sample of an array that makes up a picture of monochrome format. In some examples, a coding block is an M×N block of samples for certain values ​​of M and N, so that the division of a CTB into coding blocks is a "partition".

[0056] Blocks (e.g., CTUs or CUs) can be grouped in various ways in a picture. As an example, a brick may refer to a rectangular area of ​​a CTU row within a particular tile in a picture. A tile may be a rectangular area of ​​a CTU within a particular tile column and a particular tile row in a picture. A tile column refers to a rectangular area of ​​a CTU having a height equal to the picture height and a width specified by a syntax element (e.g., such as in a picture parameter set). A tile row refers to a rectangular area of ​​a CTU having a height specified by a syntax element (e.g., such as in a picture parameter set) and a width equal to the picture width.

[0057] In some examples, a tile may be divided into a plurality of blocks, each of which may include one or more CTU rows within the tile. A tile that is not divided into a plurality of blocks may also be referred to as a block. However, a block that is a true subset of a tile may not be referred to as a tile. Blocks in a picture may also be arranged in slices. A slice may be an integer number of blocks in a picture that may be exclusively contained in a single network abstraction layer (NAL) unit. In some examples, a slice includes several complete tiles or a continuous sequence of complete blocks that include only one tile.

[0058] This disclosure may use "N×N" and "N by N" interchangeably to refer to the sample size of a block (e.g., a CU or other video block) in terms of vertical and horizontal dimensions, such as 16×16 samples or 16 by 16 samples. Typically, a 16×16 CU has 16 samples in the vertical direction (y=16) and 16 samples in the horizontal direction (x=16). Similarly, an N×N CU typically has N samples in the vertical direction and N samples in the horizontal direction, where N represents a non-negative integer value. The samples in a CU may be arranged in rows and columns. In addition, a CU does not necessarily have the same number of samples in the horizontal direction as in the vertical direction. For example, a CU may include N×M samples, where M is not necessarily equal to N.

[0059] The video encoder 200 encodes the video data representing prediction information and / or residual information and other information of the CU. The prediction information indicates how the CU will be predicted in order to form a prediction block for the CU. The residual information generally represents the sample-by-sample difference between the samples of the CU before encoding and the prediction block.

[0060] In order to predict a CU, the video encoder 200 may generally form a prediction block for the CU by inter-frame prediction or intra-frame prediction. Inter-frame prediction generally refers to predicting a CU based on data of a previously decoded picture, while intra-frame prediction generally refers to predicting a CU based on previously decoded data of the same picture. In order to perform inter-frame prediction, the video encoder 200 may use one or more motion vectors to generate a prediction block. The video encoder 200 may generally perform motion search, for example, according to the difference between the CU and the reference block to identify a reference block that closely matches the CU. The video encoder 200 may calculate a difference metric using the sum of absolute differences (SAD), the sum of squared differences (SSD), the mean absolute difference (MAD), the mean square difference (MSD), or other such difference calculations to determine whether the reference block closely matches the current CU. In some examples, the video encoder 200 may use unidirectional prediction or bidirectional prediction to predict the current CU.

[0061] Some examples of VVC also provide an affine motion compensation mode, which can be considered an inter-frame prediction mode. In the affine motion compensation mode, the video encoder 200 can determine two or more motion vectors representing non-translational motion (e.g., zooming in or out, rotation, perspective motion, or other irregular motion types).

[0062] To perform intra prediction, the video encoder 200 may select an intra prediction mode to generate a prediction block. Some examples of VVC provide 67 intra prediction modes, including various directional modes, as well as a planar mode and a DC mode. Typically, the video encoder 200 selects an intra prediction mode that describes neighboring samples of a current block that are used to predict samples of a current block (e.g., a block of a CU). Assuming that the video encoder 200 decodes CTUs and CUs in a raster scan order (from left to right, from top to bottom), such samples may typically be above, above left, or to the left of the current block in the same picture as the current block.

[0063] The video encoder 200 encodes data representing the prediction mode of the current block. For example, for inter-frame prediction mode, the video encoder 200 can encode data indicating which of the various available inter-frame prediction modes is used and motion information of the corresponding mode. For unidirectional or bidirectional inter-frame prediction, for example, the video encoder 200 can encode the motion vector using advanced motion vector prediction (AMVP) or merge mode. The video encoder 200 can use a similar mode to encode the motion vector of the affine motion compensation mode.

[0064] AV1 includes two general techniques for encoding and decoding coded blocks of video data. The two general techniques are intra prediction (e.g., intra prediction or spatial prediction) and inter prediction (e.g., inter prediction or temporal prediction). In the context of AV1, when an intra prediction mode is used to predict a block of a current frame of video data, the video encoder 200 and the video decoder 300 do not use video data from other frames of the video data. For most intra prediction modes, the video encoder 200 encodes a block of the current frame based on the difference between the sample values ​​in the current block and the prediction values ​​generated from the reference samples in the same frame. The video encoder 200 determines the prediction values ​​generated from the reference samples based on the intra prediction mode.

[0065] After a prediction, such as intra prediction or inter prediction of a block, the video encoder 200 may calculate residual data for the block. The residual data (e.g., a residual block) represents the sample-by-sample difference between the block and a prediction block of the block formed using a corresponding prediction mode. The video encoder 200 may apply one or more transforms to the residual block to generate transformed data in a transform domain rather than a sample domain. For example, the video encoder 200 may apply a discrete cosine transform (DCT), an integer transform, a wavelet transform, or a conceptually similar transform to the residual video data. In addition, the video encoder 200 may apply a secondary transform after the first transform, such as a mode-dependent non-separable secondary transform (MDNSST), a signal-dependent transform, a Karhunen-Loeve transform (KLT), and the like. The video encoder 200 generates transform coefficients after applying one or more transforms.

[0066] As described above, after any transforms used to produce transform coefficients, the video encoder 200 may perform quantization of the transform coefficients. Quantization generally refers to the process of quantizing transform coefficients to possibly reduce the amount of data used to represent the transform coefficients, thereby providing further compression. By performing the quantization process, the video encoder 200 may reduce the bit depth associated with some or all transform coefficients. For example, the video encoder 200 may round an n-bit value to an m-bit value during quantization, where n is greater than m. In some examples, to perform quantization, the video encoder 200 may perform a bitwise right shift of the value to be quantized.

[0067] After quantization, the video encoder 200 may scan the transform coefficients to generate a one-dimensional vector from a two-dimensional matrix including the quantized transform coefficients. The scan may be designed to place transform coefficients of higher energy (and therefore lower frequency) at the front of the vector and transform coefficients of lower energy (and therefore higher frequency) at the back of the vector. In some examples, the video encoder 200 may scan the quantized transform coefficients using a predefined scan order to generate a serialized vector, and then entropy encode the quantized transform coefficients of the vector. In other examples, the video encoder 200 may perform adaptive scanning. After scanning the quantized transform coefficients to form a one-dimensional vector, the video encoder 200 may entropy encode the one-dimensional vector, for example, according to context adaptive binary arithmetic coding (CABAC). The video encoder 200 may also entropy encode the values ​​of syntax elements that describe metadata associated with the encoded video data for use by the video decoder 300 when decoding the video data.

[0068] To perform CABAC, the video encoder 200 may assign context within a context model to a symbol to be transmitted. The context may relate to, for example, whether neighboring values ​​of the symbol are zero values. The probability determination may be based on the context assigned to the symbol.

[0069] The video encoder 200 may also generate syntax data, such as block-based syntax data, picture-based syntax data, and sequence-based syntax data, for example in a picture header, a block header, a slice header, or other syntax data, such as a sequence parameter set (SPS), a picture parameter set (PPS), or a video parameter set (VPS), to the video decoder 300. The video decoder 300 may similarly decode such syntax data to determine how to decode the corresponding video data.

[0070] In this way, the video encoder 200 can generate a bitstream including encoded video data, such as: a syntax element describing the division of a picture into blocks (e.g., CUs) and prediction information and / or residual information of the blocks. Finally, the video decoder 300 can receive the bitstream and decode the encoded video data.

[0071] In general, the video decoder 300 performs a reciprocal process of the process performed by the video encoder 200 to decode the encoded video data of the bitstream. For example, the video decoder 300 may use CABAC to decode the values ​​of the syntax elements of the bitstream in a manner that is substantially similar to the CABAC encoding process of the video encoder 200, although reciprocal. The syntax elements may define partitioning information for partitioning a picture into CTUs, and partitioning each CTU according to a corresponding partitioning structure (e.g., a QTBT structure) to define CUs of the CTU. The syntax elements may further define prediction information and residual information for a block (e.g., a CU) of video data.

[0072] The residual information may be represented by, for example, quantized transform coefficients. The video decoder 300 may inverse quantize and inverse transform the quantized transform coefficients of the block to reproduce the residual block of the block. The video decoder 300 uses the prediction mode (intra-frame prediction or inter-frame prediction) and the related prediction information (e.g., motion information for inter-frame prediction) signaled to form a prediction block for the block. The video decoder 300 may then combine the prediction block and the residual block (on a sample-by-sample basis) to reproduce the original block. The video decoder 300 may perform additional processing, such as performing a deblocking process to reduce visual artifacts along the boundaries of the block. The present disclosure may generally refer to "signaling" certain information, such as syntax elements. The term "signaling" may generally refer to the communication of the values ​​of syntax elements and / or other data used to decode the encoded video data. That is, the video encoder 200 may signal the values ​​of syntax elements in the bitstream. Generally, signaling refers to generating values ​​in the bitstream. As described above, source device 102 may transmit the bitstream to destination device 116 in substantially real time or in non-real time (such as may occur when storing syntax elements to storage device 112 for later retrieval by destination device 116 ).

[0073] According to the techniques of the present disclosure, as will be explained in more detail below, the video encoder 200 and the video decoder 300 may be configured to generate a fusion of predictors from two or more sample reference rows relative to a block of video data based on an intra-frame prediction mode, and to encode / decode the block of video data using the fusion of predictors and the intra-frame prediction mode.

[0074] Intra-frame prediction

[0075] Intra prediction is a basic component in many video codecs. For a current coding unit 130 ("CU 130"), predictions for samples inside CU 130 can be generated from reference rows 132 according to different intra prediction modes, such as planar mode, DC mode, and one of a plurality of angular modes (also referred to as directional modes). In one example, the default sample reference row is the sample row closest to CU 130, such as Figure 2 For angle mode, based on the mode direction, the video coder may determine whether to perform interpolation of reference samples with a 6-tap / 4-tap filter, smoothing with a Gaussian filter, or directly copying reference sample values.

[0076] Multiple Reference Line (MRL)

[0077] like Figure 3 As shown, the default sample reference row may be row 132A (e.g., "row 0"), which is directly adjacent to the top and to the left of the current decoding unit. In MRL mode, the video decoder may be configured to use other reference rows, such as rows 132B-N (generally referred to as "row 132", which may correspond to the second row, the third row, the fourth row, etc.). For ease of illustration, Figure 3 Only rows 132A-132E are shown.This MRL mode is called Multiple Reference Line (MRL) in the Enhanced Compression Model (ECM) developed by JVET.

[0078] Decoder-side intra mode derivation (DIMD)

[0079] In addition to the plane mode, DC mode and angle mode, another intra prediction mode is decoder side intra mode derivation (DIMD), in which the video decoder 300 is configured to derive the intra coding mode from the decoder side. In some examples, the video decoder 300 may be configured to derive the intra coding mode using a histogram of gradients (HoG). For example, HOG may be or otherwise represent a vector of length 67, wherein each element represents the magnitude of the corresponding direction. HOG may create hints for possible angle modes. For the current coding unit (CU), the video decoder 300 may calculate the HOG using reconstructed samples from the reconstructed neighbors above, the reconstructed neighbors on the left, and the upper left corner neighbors.

[0080] In some examples, the video decoder 300 may implement DIMD by fusing predictors from multiple intra prediction modes. For example, the video decoder 300 may fuse the predictors from two angular modes with the highest magnitudes (e.g., based on HOG) with the planar mode to determine the final prediction from DIMD. The two angular modes may be mode1 and mode2, and the magnitudes of mode1 and mode2 may be mag1 and mag2, respectively. In some examples, the video decoder 300 may determine the weights for the fusion of mode1, mode2, and the planar mode as and 1 / 3, respectively.

[0081] Template-based Intra Mode Derivation (TIMD)

[0082] Another decoder-side intra mode derivation method is template-based intra mode derivation. Figure 4 is a conceptual diagram showing example templates and reference samples used in template-based intra mode derivation. Given a CU 130, the video decoder 300 may select two template regions 134A - 134B (e.g., above the CU 130 and to the left of the CU 130) and the corresponding reference template 136. For each mode in the most probable mode (MPM) list, the video decoder 300 may generate a prediction for the template region 136 and calculate the sum of the absolute transform difference (SATD) costs over the template region 136 between the prediction and the reconstructed samples. The video decoder 300 may select the mode with the lowest cost as the mode for TIMD.

[0083] The video decoder 300 may determine mode1 and mode2 with the minimum SATD cost. The costs of mode1 and mode2 may be cost1 and cost2, respectively. In some examples, in response to determining that 2 * cost1 < cost2, the video decoder 300 may fuse mode1 and mode2 and determine the weights for the fusion of mode1 and mode2 as and Otherwise, the video decoder 300 may use mode1 without fusion.

[0084] Angle mode with integer slope / non-integer slope

[0085] Figure 5 is a conceptual diagram showing example angular intra prediction modes in one version of ECM. In Figure 5 each arrow corresponds to a different angular mode indicating a different direction in ECM. For different directions, some directions fall between the reference samples and some directions fall on the reference samples, as Figure 6 shown. Figure 6 is a conceptual diagram showing examples of integer slopes and non-integer slopes for angular intra prediction modes. Figure 6 In , directions that fall on the reference samples have integer slopes, and those that fall between the reference samples have non-integer slopes. Figure 5 and 6 , solid arrows 140 correspond to directions having integer slopes, while dashed arrows 142 correspond to directions having non-integer slopes.

[0086] Most Probable Mode (MPM) List

[0087] In some examples of intra-frame prediction, the video encoder 200 and the video decoder 300 can generate a list of most probable modes (e.g., an MPM list) for each prediction unit (PU). When encoding the prediction mode, the video encoder 200 can encode the index to the MPM list of the actually selected mode instead of writing the mode directly into the bitstream. The video decoder 300 can then use this index as input to the MPM list generated at the video decoder to determine the intra-frame prediction mode.

[0088] In ECM, the length of the MPM list is 22 and may include two parts. The first 6 modes in the MPM list may be referred to as the main MPM list. They may include a plane mode, a mode from the left PU, a mode from the upper PU, a mode from the lower left PU, a mode from the upper right PU, and a mode from the upper left PU. The next 16 modes in the MPM list may be referred to as a secondary MPM list, which may include modes derived by offsets from modes in the main MPM list. The video encoder 200 and the video decoder 300 may add DIMD modes (e.g., mode1 and mode2) after the main MPM list and before the secondary MPM list in the final MPM list.

[0089] The video encoder 200 and the video decoder 300 may add all modes not included in the MPM list to the non-MPM list. The video encoder 200 and the video decoder 300 may also generate a separate MPM list for the chroma channel, where the first 4 modes of the chroma MPM list correspond to the modes in the luma MPM list.

[0090] In the example of ECM software, intra prediction uses only one reference row for CU sample prediction. Even when MRL mode is enabled, the video decoder 300 may use only one reference row, which may reduce prediction accuracy in some cases.

[0091] Several methods for solving the above problems are described in the present disclosure. The techniques of the present disclosure can be used individually or in any combination. According to the techniques of the present disclosure, the video decoder 300 can decode video data by generating a fusion of predictors from two or more sample reference rows relative to a block of video data based on an intra-frame prediction mode. By fusing predictors from two or more reference rows, the system can generate more accurate predictions, which can not only result in smaller residual data that can be compressed more efficiently, but also improve visual quality. In addition, these techniques can result in faster decoding times and lower computing resource requirements.

[0092] The video encoder 200 and the video decoder 300 may generate a fusion of predictors from two or more sample reference rows relative to a block of video data based on an intra prediction mode. In some examples, the video encoder 200 and the video decoder 300 may generate a fusion of predictors based on a weighted combination of predictors from two or more sample reference rows based on an intra prediction mode. For example, the video encoder 200 and the video decoder 300 may select the reference row for the predictor as a conventional default reference row (e.g., Figure 3 132A) and other different reference lines (e.g. Figure 3 The other reference rows may be a single reference row or more than one reference row.

[0093] In another example, the video encoder 200 and the video decoder 300 may select the reference row for the predictor to be, for example, a combination of any two intra-frame predictors derived from any two reference rows. The rows may be different. In some examples, the video encoder 200 and the video decoder 300 may generate a fusion of predictors based on a weighted combination of predictors from two or more intra-frame modes derived from the same reference row but using different intra-frame prediction methods.

[0094] The video encoder 200 and the video decoder 300 may be configured to generate a fusion of predictors from two or more sample reference rows relative to a block of video data, and to decode (e.g., encode or decode) the block of video data using the fusion of predictors and an intra prediction mode. In one example, the two or more sample reference rows include a default sample reference row, e.g. Figure 3 In another example, the default sample reference row is adjacent to the video data block (e.g., row 132A adjacent to CU 130). Figure 3 132A-132B, which may correspond to row 0 and row 1). Generally, the two or more reference rows may include any one of rows 132.

[0095] The video encoder 200 and the video decoder 300 may be configured to determine a predictor from two or more sample reference rows using the same intra prediction mode. In another example, the video encoder 200 and the video decoder 300 may be configured to determine a predictor from two or more sample reference rows using at least two different intra prediction modes. In some examples, the at least two different intra prediction modes may be angle modes. In any case, the video encoder 200 and the video decoder 300 apply intra prediction fusion to an intra prediction mode with a non-integer slope.

[0096] In one example, the video encoder 200 and the video decoder 300 may be configured to select the reference row as a subset of the rows used in the MRL prediction. That is, the sample reference row may be a subset of the sample reference row set for the MRL decoding mode. In one example, the subset of the sample reference row set includes a default sample reference row adjacent to the video data block, and other sample reference rows adjacent to the default sample reference row. For example, the video encoder 200 and the video decoder 300 may use row 0 as the default reference row, and row 1 as the other reference row. Therefore, if the MRL mode is applied to the default reference row set {1, 3, 5, 7, 12}, when the fusion is used in conjunction with MRL, the row set may include {[1, 2], [3, 4], [5, 6], [7, 8], [12, 13]}). In another example, the video encoder 200 and the video decoder 300 may use non-adjacent rows as the other reference rows (e.g., if row 1 is the default reference row, such as row 3 and row 5).

[0097] In another example, the video encoder 200 and the video decoder 300 may select the other reference rows as reference rows that are a certain distance from the conventional default reference row. For example, the other reference rows may be adjacent reference rows, which are row 1. In another example, the video encoder 200 and the video decoder 300 may specifically select the other reference rows as rows that are not used in MRL prediction to provide diversity. For example, the other reference rows may be rows 2 and 4, which are not used in the current MRL mode. In another example, the other reference rows may also be a mixture of reference rows used and not used in MRL.

[0098] Several selection techniques are described above. However, the video encoder 200 and the video decoder 300 may use other techniques to identify the other reference rows for the blend mode, and such techniques should be considered within the scope of the present disclosure.

[0099] In one example, the video encoder 200 and the video decoder 300 may implement fusion of two or more intra predictors by determining a weighted combination of predictors from multiple reference lines. For example, the video encoder 200 and the video decoder 300 may use the equation To calculate the fusion of predictors, where p fusion represents the fused reference intra-frame prediction value, w i represents the weight of the predictor with index position i, and p i Represents the intra-frame prediction value of the predictor with index position i. For example, the video encoder 200 and the video decoder 300 may apply a first weight to the predictors in the default reference row and a second weight to the predictors in the other reference rows. The default reference row may be closer to the video data block than the other reference rows. In any case, the video encoder 200 and the video decoder 300 may select these reference rows using any of the methods described herein.

[0100] In one example, the weight of each predictor may be fixed. For example, the video encoder 200 and the video decoder 300 may apply fusion to the intra-prediction value derived from one reference line (denoted as p0) and the intra-prediction value derived from the other reference line (denoted as p1). The video encoder 200 and the video decoder 300 may use the equation p fusion =w0p0+w1p1 to calculate the fusion of the predictors. In one example, the video encoder 200 and the video decoder 300 may determine that the fixed weights are w0=3 / 4 and w1=1 / 4. That is, the video encoder 200 and the video decoder 300 may determine that the first weight is 0.75 and the second weight is 0.25.

[0101] In another example, the video encoder 200 and the video decoder 300 may determine weights (e.g., first weights, second weights, etc.) based on the position of the current sample in the block, and one or more of the width or height of the block. The current sample position may be (x, y), and the current coding unit size may be (w, h). For example, the video encoder 200 and the video decoder 300 may use the equations w0=y / h and w1=1-y / h to determine weights associated with the position. In another example, the video encoder 200 and the video decoder 300 may use the equations w0=1-x / w and w1=x / w to determine weights associated with the position.

[0102] In another example, the video encoder 200 and the video decoder 300 may determine the weights based on certain criteria, such as the satisfaction of a threshold. For example, in response to the absolute value of the first predictor minus the second predictor (e.g., |p0-p1|) satisfying the threshold (e.g., being greater than or equal to the threshold), the video encoder 200 and the video decoder 300 may determine that the first weight is 0.75 and the second weight is 0.25. In response to the absolute value of the first predictor minus the second predictor not satisfying the threshold, the video encoder 200 and the video decoder 300 may determine that the first weight is 0.5 and the second weight is 0.5.

[0103] In another example, the video encoder 200 and the video decoder 300 may determine the weights based on the cost of a template used in intra prediction (e.g., SATD used in TIMD). In one example, the SATD cost of the first intra predictor is cost1, and cost2 is the SATD cost of the second intra predictor. The video encoder 200 and the video decoder 300 may use the equation and To determine the weight, where w0+w1=1.

[0104] In one example, the video encoder 200 and the video decoder 300 may implement fusion by adding weighted gradients between the predictors. In one example, the video encoder 200 and the video decoder 300 may implement fusion by using the equation To achieve fusion, where p fusion represents the fused reference intra-frame prediction value, w i represents the weight of the predictor with index position i, p i denotes the intra prediction value of the predictor with index position i, and p0 denotes the intra prediction value of the predictor from the first or default reference row. As described above, the weights may be fixed, depending on the pixel / sample position, on some criteria or cost from a template, etc.

[0105] In one example, the video encoder 200 and the video decoder 300 may implicitly apply intra-prediction fusion. For example, the video encoder 200 and the video decoder 300 may apply intra-prediction fusion regardless of the intra-mode or CU size involved. In another example, the video encoder 200 and the video decoder 300 may explicitly apply intra-prediction fusion. The video encoder 200 may encode and signal a flag in the bitstream at the CU level or the slice level to indicate whether intra-prediction fusion is applied.

[0106] In one example, whether the video encoder 200 and the video decoder 300 apply intra-prediction fusion may depend on the intra-mode. In one example, the video encoder 200 and the video decoder 300 may apply intra-prediction fusion to any intra-mode, such as planar mode, DC mode, and angular mode. In another example, the video encoder 200 and the video decoder 300 may apply intra-prediction fusion to only a subset of intra-modes (e.g., only to angular modes). In another example, the video encoder 200 and the video decoder 300 may apply intra-prediction fusion to only modes with non-integer slopes (e.g., such as angular modes). Figure 5-6 Examples of intra prediction modes with non-integer slopes may include Figure 5 The dashed line 142 is shown in FIG.

[0107] The video encoder 200 and the video decoder 300 may use other conditions to identify the intra-mode subset used or whether to apply fusion, and these conditions should also be considered within the scope of the present disclosure. The video encoder 200 and the video decoder 300 may use explicit conditions to check whether the disclosed fusion mode is applied and to which intra-modes. If all modes meet the conditions, the video encoder 200 and the video decoder 300 may apply the disclosed fusion method to all intra-modes; otherwise, the video encoder 200 and the video decoder 300 may not apply fusion. In another example, if any of the modes involved meet the conditions, and other modes may or may not follow the conditions, the video encoder 200 and the video decoder 300 may apply the disclosed fusion method. The difference between the two examples is that in the first case, both mode0 and mode1 must meet the conditions, while in the second example, only mode0 or mode1 needs to meet the conditions, but the other mode may or may not meet the conditions.

[0108] The video encoder 200 and the video decoder 300 may apply one or more interpolation filters to a block of video data. The video encoder 200 and the video decoder 300 may derive prediction samples from reference samples after interpolation using any type of filter (e.g., a 6-tap filter or a 4-tap filter). In some examples, the video encoder 200 and the video decoder 300 may derive prediction samples from a mixture of different types of filters. For example, the video encoder 200 and the video decoder 300 may derive one prediction sample from a 6-tap interpolation filter and another prediction sample from a 4-tap interpolation filter.

[0109] In one example, whether the video encoder 200 and the video decoder 300 apply intra prediction fusion depends on the block size. In one example, when the CU area is greater than N, the video encoder 200 and the video decoder 300 may apply intra prediction fusion, where N is equal to 32, for example.

[0110] In another example, intra prediction fusion may depend on the prediction mode used to decode the current block. For example, when the current intra mode is DIMD mode or TIMD mode, the video encoder 200 and the video decoder 300 may disable intra prediction fusion. For another example, when the CU 130 is decoded in intra sub-partitioning (ISP) mode, the video encoder 200 and the video decoder 300 may disable intra prediction fusion. That is, when the ISP mode is disabled, the video encoder 200 and the video decoder 300 may use intra prediction fusion (e.g., generating a fusion of predictors from multiple sample reference rows).

[0111] In another example, the video encoder 200 and the video decoder 300 can combine intra-prediction fusion with other prediction modes (e.g., TIMD / DIMD) using other types of fusion. Since these modes (TIMD or DIMD) may have utilized other fusions, the video encoder 200 and the video decoder 300 can apply fusion in a one-stage or two-stage process. In the case of two-stage fusion, the video encoder 200 and the video decoder 300 can first apply intra-prediction fusion according to the technology for each mode from TIMD and DIMD. Then, the video encoder 200 and the video decoder 300 can apply fusion specific to those modes in the second stage. In this case, the video encoder 200 and the video decoder 300 can separate the weights for intra-prediction fusion and TIMD / DIMD mode fusion. The video encoder 200 and the video decoder 300 can determine that the weights for intra-prediction are 3 / 4 and 1 / 4, and independently determine the fusion weights for the TIMD / DIMD mode.

[0112] In a one-stage fusion example, for each TIMD / DIMD mode, the video encoder 200 and the video decoder 300 can derive two or more predictors from different reference lines. The video encoder 200 and the video decoder 300 can fuse these predictors together to avoid rounding errors caused by fusion. For example, if TIMD / DIMD uses intra mode 0 and intra mode 1 in prediction, the video encoder 200 and the video decoder 300 can use different reference lines from intra mode 0 to derive two predictors, which can be represented as intra mode 00 and mode 01. Similarly, the video encoder 200 and the video decoder 300 can use different reference lines from intra mode 1 to derive two predictors, which can be represented as intra mode 10 and mode 11. In a one-stage fusion, the video encoder 200 and the video decoder 300 can fuse these 4 modes (mode 00, mode 01, mode 10, mode 11) together with certain weights. The video encoder 200 and the video decoder 300 may apply the same or substantially similar techniques to more than two predictors derived using more than two reference rows.

[0113] In the two-stage process, the video encoder 200 and the video decoder 300 can derive Mode 0 from Mode 00 and Mode 01 by using the described method. Similarly, the video encoder 200 and the video decoder 300 can derive Mode 1 from Mode 10 and Mode 11, which represents the first stage. Then, as a second stage, the video encoder 200 and the video decoder 300 can fuse Modes 0 and 1 according to a fusion method specific to TIMD / DIMD.

[0114] The video encoder 200 and the video decoder 300 can derive the weights in the one-stage process by multiplying the fixed weights w0 and w1 of the disclosed method with the weights used in TIMD and DIMD. In another alternative, the video encoder 200 and the video decoder 300 can derive the weights of the involved modes based on the template cost.

[0115] In an example where intra prediction fusion using TIMD / DIMD is enabled, the video encoder 200 and the video decoder 300 may apply a position-dependent intra prediction combination (PDPC) process only once for each predictor at the end of mode fusion. In another example, the video encoder 200 and the video decoder 300 may apply the PDPC process immediately after each predictor.

[0116] In one example, the video encoder 200 and the video decoder 300 may apply intra-prediction fusion combined with other tools such as MRL, ISP, and matrix-based intra prediction (MIP). When intra-prediction fusion with MRL is enabled, the video encoder 200 and the video decoder 300 may use a default reference row to derive the MRL prediction (typically signaled in the bitstream as an MRL index), and the video encoder 200 and the video decoder 300 may select other reference rows from the rows that can be used in the MRL prediction. For example, if the video encoder 200 and the video decoder 300 use row 3 as the current reference row, the video encoder 200 and the video decoder 300 may select row 5 as the other reference row. In another example, if the video encoder 200 and the video decoder 300 use row 3 as the current reference row, the video encoder 200 and the video decoder 300 may select row 1 as the other reference row. In yet another example, if the video encoder 200 and the video decoder 300 use row 3 as the current reference row, the video encoder 200 and the video decoder 300 may select row 5 and row 7 as the other reference rows.

[0117] In another example, the video encoder 200 and the video decoder 300 may apply the intra prediction fusion techniques of the present disclosure to a subset of the MRL candidate list. For example, the video encoder 200 and the video decoder 300 may apply intra prediction fusion to the first three candidates in the MRL candidate list.

[0118] In some examples, the video encoder 200 and the video decoder 300 may apply intra-prediction fusion with mode signaling. In one example, the video encoder 200 and the video decoder 300 may first construct a candidate list to include all modes, such as DC, plane, angle mode, TIMD, and DIMD mode. The modes in the list may come from the MPM list, from a preset intra-mode list, such as {plane mode, DC mode, horizontal, vertical}, or from a mode list after the video encoder 200 and the video decoder 300 run the first round of SATD checks.

[0119] The intra mode list may be composed of intra direction and other intra prediction methods as a combination. For example, the entries of the intra mode list may be composed of {intra direction, MRL index, whether to apply fusion} and similar combinations. The video encoder 200 and the video decoder 300 may send an index to the intra mode list instead of signaling the intra direction, MRL index and fusion flag.

[0120] Two entries can be different if, for example, at least one of the components of the combination is different. For example, {intra direction 10, MRL index 3, no fusion} is different from {intra direction 10, MRL index 1, no fusion}, and is also different from {intra direction 10, MRL index 1, apply fusion}.

[0121] The length of the list can be fixed or defined adaptively. For example, video encoder 200 and video decoder 300 can use the reconstructed neighbor samples and intra modes to decode neighbor blocks. Video encoder 200 and video decoder 300 can apply sorting or reorder the entries in the intra mode list. In one example, video encoder 200 and video decoder 300 can sort the entries based on a cost metric indicating the efficiency of the entry. This cost metric can be any cost function, such as SATD, mean squared error (MSE), or SAD cost derived from the predicted and reconstructed neighbor samples for a given entry in the intra mode list.

[0122] In cases where the reconstructed neighbor samples have been derived, video encoder 200 and video decoder 300 can use different entries to derive intra predictions for the same neighbor samples. Video encoder 200 and video decoder 300 can then apply a cost function to the difference between the predicted and reconstructed neighbor samples. Those neighbor samples can be the samples to the left or above the block. In another example, the neighbor samples can include left, above, top-right, top-left, and bottom-left neighbor samples. More generally, the neighbor template can include those samples and can include more than 1 row or 1 column of such samples.

[0123] In one example, the intra mode list includes only a subset of the intra modes, optionally after applying sorting. For example, the total list size can include N modes, and after sorting, only the first M modes are retained in the list, where M < N. Video encoder 200 and video decoder 300 can signal the entry indices of the pruned mode list in the bitstream to indicate the entries to be used for decoding the intra-coded blocks. In one example, these entries can consist of intra MPM modes and other intra prediction methods that can be enabled or disabled by video encoder 200 and video decoder 300 for a certain entry.

[0124] In another example, video encoder 200 and video decoder 300 can always enable or disable certain intra methods for all entries or a subset of the entries in the intra mode list. For example, video encoder 200 and video decoder 300 can apply intra prediction fusion to all the modes in the candidate list. In another example, video encoder 200 and video decoder 300 can first construct the candidate list with intra prediction fusion disabled.

[0125] In some examples, the video encoder 200 and the video decoder 300 may use a subset of all possible components without always applying intra-prediction fusion. The video encoder 200 and the video decoder 300 may sort and prune the entries based on the entry cost function to reduce the list to the desired size. The video encoder 200 and the video decoder 300 may add entries to the list of initial entries included in the case of enabling intra-prediction fusion. In one example, the size of the candidate list with the remaining modes can be doubled by adding pruned modes with intra-prediction fusion. The video encoder 200 and the video decoder 300 may then apply a second round of pruning using the cost to the candidate list to select the top P modes in the candidate list with the smallest cost, for example, P=10. The video encoder 200 and the video decoder 300 may signal the index of the selected mode in the bitstream.

[0126] Cost-based pruning can be an operation that indicates which intra-modes can be removed from the list. In one example, if two costs are close, for example, the absolute difference is less than a threshold, such entries can be considered equivalent, and the video encoder 200 and the video decoder 300 can remove one entry from the list, for example, the entry with a larger index.

[0127] In another example, the video encoder 200 and the video decoder 300 may construct a separate MPM list or auxiliary MPM list, which may be a subgroup of a larger MPM list related to intra-frame fusion mode based on the mode from the neighbor CU and the intra-frame mode of the neighboring block. The video encoder 200 and the video decoder 300 may enable intra-frame prediction fusion for all modes in such a fused MPM list or subgroup.

[0128] In some examples, the video encoder 200 and the video decoder 300 may select the other reference rows as rows that are not applied in any MRL prediction. For example, when row 3 is the current reference row and row 4 is the other reference row, the video encoder 200 and the video decoder 300 may not use row 4 in MRL, which can provide intra-frame prediction diversity. In another example, the video encoder 200 and the video decoder 300 may select a reference row that has a distance l from the current reference row as the other reference row. For example, l=1 may indicate that the other reference row is an upper adjacent reference row. In another example, l=-1 may indicate that the other reference row is a lower adjacent reference row.

[0129] In one example, the video encoder 200 and the video decoder 300 may check the CTU boundary before implementing the disclosed intra-frame prediction fusion method. If the other reference lines are outside the CTU boundary and optionally also outside the existing line buffer (e.g., reference lines stored for an already existing intra-frame prediction method), the video encoder 200 and the video decoder 300 may disable the disclosed fusion mode technology. In another example, the video encoder 200 and the video decoder 300 may always enable fusion regardless of the CTU boundary configuration.

[0130] The video encoder 200 and the video decoder 300 may filter the fusion of the predictors using a two-dimensional (2D) filter, such as a low-pass filter, a high-pass filter, etc., to generate one or more prediction samples. For example, the video encoder 200 and the video decoder 300 may use multiple reference lines as inputs to the 2D filter to generate prediction samples. In one example, the 2D filter may represent an interpolation or smoothing applied to the reference sample and the disclosed intra-frame prediction fusion to generate an intra-frame predictor. For example, the 2D filter may be a 2 by 3 low-pass filter. In another example, the 2D filter may be a 3×3 high-pass filter. The video encoder 200 and the video decoder 300 may use one or more prediction samples to decode a block of video data.

[0131] Figure 7 is a block diagram illustrating an example video encoder 200 that may perform the techniques of this disclosure. Figure 7 For purposes of illustration, and should not be considered limiting of the techniques broadly illustrated and described in this disclosure. For purposes of illustration, this disclosure describes a video encoder 200 in accordance with techniques of VVC (ITU-T H.266, under development) and HEVC (ITU-T H.265). However, the techniques of this disclosure may be performed by a video encoding device configured for other video coding standards and video coding formats, such as AV1 and successors to the AV1 video coding format.

[0132] exist Figure 7In the example of , the video encoder 200 includes a video data memory 230, a mode selection unit 202, a residual generation unit 204, a transform processing unit 206, a quantization unit 208, an inverse quantization unit 210, an inverse transform processing unit 212, a reconstruction unit 214, a filter unit 216, a decoded picture buffer (DPB) 218, and an entropy coding unit 220. Any one or all of the video data memory 230, the mode selection unit 202, the residual generation unit 204, the transform processing unit 206, the quantization unit 208, the inverse quantization unit 210, the inverse transform processing unit 212, the reconstruction unit 214, the filter unit 216, the DPB 218, and the entropy coding unit 220 may be implemented in one or more processors or in processing circuits. For example, the units of the video encoder 200 may be implemented as one or more circuits or logic elements as part of a hardware circuit or as part of a processor, ASIC, or FPGA. In addition, the video encoder 200 may include additional or alternative processors or processing circuits to perform these and other functions.

[0133] The video data memory 230 may store video data to be encoded by the components of the video encoder 200. The video encoder 200 may receive video data from, for example, the video source 104 ( Figure 1 ) receives video data stored in video data memory 230. DPB 218 can be used as a reference picture memory that stores reference video data for use by the video encoder 200 when predicting subsequent video data. Video data memory 230 and DPB 218 can be formed by any of a variety of storage devices, such as dynamic random access memory (DRAM), including synchronous DRAM (SDRAM), magnetoresistive RAM (MRAM), resistive RAM (RRAM) or other types of storage devices. Video data memory 230 and DPB 218 can be provided by the same storage device or a separate storage device. In various examples, video data memory 230 can be on-chip with other components of video encoder 200 (as shown), or off-chip relative to those components.

[0134] In the present disclosure, references to the video data memory 230 should not be construed as limited to memory internal to the video encoder 200, unless specifically described as such, or memory external to the video encoder 200, unless specifically described as such. Rather, references to the video data memory 230 should be understood as a reference memory that stores video data received by the video encoder 200 for encoding (e.g., video data of a current block to be encoded). Figure 1 The memory 106 may also provide temporary storage for the outputs of the various units of the video encoder 200 .

[0135] Show Figure 7 The various units of the video encoder 200 are provided to help understand the operations performed by the video encoder 200. These units can be implemented as fixed-function circuits, programmable circuits, or a combination thereof. Fixed-function circuits refer to circuits that provide specific functions and are pre-set to executable operations. Programmable circuits refer to circuits that can be programmed to perform various tasks and provide flexible functions in executable operations. For example, a programmable circuit can execute software or firmware that causes the programmable circuit to operate in a manner defined by the instructions of the software or firmware. Fixed-function circuits can execute software instructions (e.g., to receive parameters or output parameters), but the type of operation performed by the fixed-function circuit is generally immutable. In some examples, one or more of the units may be different circuit blocks (fixed-function or programmable), and in some examples, one or more of the units may be integrated circuits.

[0136] The video encoder 200 may include an arithmetic logic unit (ALU), an elementary function unit (EFU), a digital circuit, an analog circuit, and / or a programmable core formed by a programmable circuit. In an example where the operation of the video encoder 200 is performed using software executed by a programmable circuit, the memory 106 ( Figure 1 ) may store instructions (eg, object code) for software received and executed by the video encoder 200, or another memory (not shown) within the video encoder 200 may store such instructions.

[0137] The video data memory 230 is configured to store received video data. The video encoder 200 may retrieve a picture of video data from the video data memory 230 and provide the video data to the residual generation unit 204 and the mode selection unit 202. The video data in the video data memory 230 may be original video data to be encoded.

[0138] The mode selection unit 202 includes a motion estimation unit 222, a motion compensation unit 224, and an intra prediction unit 226. The mode selection unit 202 may include other functional units to perform video prediction according to other prediction modes. As an example, the mode selection unit 202 may include a palette unit, an intra-block copy unit (which may be part of the motion estimation unit 222 and / or the motion compensation unit 224), an affine unit, a linear model (LM) unit, and the like.

[0139] The mode selection unit 202 typically coordinates multiple encoding passes to test combinations of encoding parameters and the resulting rate-distortion values ​​for such combinations. The encoding parameters may include: CTU to CU partitioning, prediction mode for CU, transform type for CU residual data, quantization parameter for CU residual data, etc. The mode selection unit 202 may ultimately select a combination of encoding parameters that has a better rate-distortion value than other tested combinations.

[0140] The video encoder 200 may divide the picture retrieved from the video data memory 230 into a series of CTUs and encapsulate one or more CTUs in a slice. The mode selection unit 202 may divide the CTUs of the picture according to a tree structure (e.g., the MTT structure, QTBT structure, super block structure, or quadtree structure described above). As described above, the video encoder 200 may form one or more CUs by dividing the CTUs according to the tree structure. Such CUs are also generally referred to as "video blocks" or "blocks".

[0141] Typically, the mode selection unit 202 also controls its components (e.g., the motion estimation unit 222, the motion compensation unit 224, and the intra prediction unit 226) to generate a prediction block for the current block (e.g., the CU 130, or in HEVC, the overlapping portion of the PU and TU). In order to inter-predict the current block, the motion estimation unit 222 may perform a motion search to identify one or more closely matching reference blocks in one or more reference pictures (e.g., one or more previously decoded pictures stored in the DPB 218). Specifically, the motion estimation unit 222 may calculate a value representing the degree of similarity of the potential reference block to the current block, for example, based on the sum of absolute differences (SAD), the sum of squared differences (SSD), the mean absolute difference (MAD), the mean squared difference (MSD), etc. The motion estimation unit 222 may generally perform these calculations using the sample-by-sample difference between the current block and the reference block under consideration. The motion estimation unit 222 may identify the reference block having the lowest value resulting from these calculations, which indicates the reference block that most closely matches the current block.

[0142] The motion estimation unit 222 may form one or more motion vectors (MVs) that define the position of a reference block in a reference picture relative to the position of a current block in a current picture. The motion estimation unit 222 may then provide the motion vectors to the motion compensation unit 224. For example, for unidirectional inter prediction, the motion estimation unit 222 may provide a single motion vector, while for bidirectional inter prediction, the motion estimation unit 222 may provide two motion vectors. The motion compensation unit 224 may then use the motion vectors to generate a prediction block. For example, the motion compensation unit 224 may use the motion vectors to retrieve data for the reference block. As another example, if the motion vectors have fractional sample precision, the motion compensation unit 224 may interpolate the values ​​of the prediction block according to one or more interpolation filters. In addition, for bidirectional inter prediction, the motion compensation unit 224 may retrieve data for two reference blocks identified by the corresponding motion vectors and combine the retrieved data, such as by sample-by-sample averaging or weighted averaging.

[0143] When operating according to the AV1 video coding format, the motion estimation unit 222 and the motion compensation unit 224 may be configured to encode coding blocks of the video data (e.g., both luma coding blocks and chroma coding blocks) using translational motion compensation, affine motion compensation, overlapped block motion compensation (OBMC), and / or composite inter-intra prediction.

[0144] As another example, for intra prediction or intra prediction decoding, the intra prediction unit 226 can generate a prediction block based on samples adjacent to the current block. For example, for directional mode, the intra prediction unit 226 can generally mathematically combine the values ​​of adjacent samples and fill these calculated values ​​across the current block in a defined direction to produce a prediction block. As another example, for DC mode, the intra prediction unit 226 can calculate the average value of adjacent samples of the current block and generate a prediction block to include the resulting average value for each sample of the prediction block.

[0145] When operating according to the AV1 video coding format, the intra prediction unit 226 may be configured to encode coding blocks of video data (e.g., both luma coding blocks and chroma coding blocks) using directional intra prediction, non-directional intra prediction, recursive filter intra prediction, luma to chroma (CFL) prediction, intra block copy (IBC), and / or palette mode. The mode selection unit 202 may include additional functional units to perform video prediction according to other prediction modes.

[0146] The intra prediction unit 226 may generate a fusion of predictors from two or more sample reference rows relative to a block of video data based on an intra prediction mode, as described herein. In some examples, the intra prediction unit 226 may generate a fusion of predictors based on a weighted combination of predictors from two or more sample reference rows based on the intra prediction mode. In some examples, the intra prediction unit 226 may select a reference row for a predictor as, for example, a combination of any two intra predictors derived from any two reference rows.

[0147] In some examples, the intra prediction unit 226 may generate a fusion of predictors based on a weighted combination of predictors from two or more intra modes derived from the same reference row but using different intra prediction methods. The intra prediction unit 226 may be configured to generate a fusion of predictors from two or more sample reference rows relative to a block of video data, and encode the block of video data using the fusion of predictors and the intra prediction mode. In some examples, the intra prediction unit 226 may apply intra prediction fusion only to modes with non-integer slopes.

[0148] The mode selection unit 202 provides the prediction block to the residual generation unit 204. The residual generation unit 204 receives the original uncoded version of the current block from the video data memory 230 and the prediction block from the mode selection unit 202. The residual generation unit 204 calculates the sample-by-sample difference between the current block and the prediction block. The resulting sample-by-sample difference defines a residual block for the current block. In some examples, the residual generation unit 204 may also determine the difference between the sample values ​​in the residual block to generate the residual block using residual differential pulse code modulation (RDPCM). In some examples, the residual generation unit 204 may be formed using one or more subtractor circuits that perform binary subtraction.

[0149] In the example where the mode selection unit 202 divides the CU into PUs, each PU may be associated with a luma prediction unit and a corresponding chroma prediction unit. The video encoder 200 and the video decoder 300 may support PUs of various sizes. As described above, the size of the CU may refer to the size of the luma coding block of the CU 130, and the size of the PU may refer to the size of the luma prediction unit of the PU. Assuming that the size of a particular CU is 2N×2N, the video encoder 200 may support PU sizes of 2N×2N or N×N for intra-frame prediction, and symmetrical PU sizes of 2N×2N, 2N×N, N×2N, N×N or the like for inter-frame prediction. The video encoder 200 and the video decoder 300 may also support asymmetric partitioning of PU sizes of 2N×nU, 2N×nD, nL×2N, and nR×2N for inter-frame prediction.

[0150] In an example where mode selection unit 202 does not further divide a CU into PUs, each CU may be associated with a luma coding block and a corresponding chroma coding block. As described above, the size of a CU may refer to the size of the luma coding block of the CU. Video encoder 200 and video decoder 300 may support CU sizes of 2N×2N, 2N×N, or N×2N.

[0151] For other video coding techniques (such as intra block copy mode coding, affine mode coding, and linear model (LM) mode coding, as some examples), the mode selection unit 202 generates a prediction block for the current block being encoded through the corresponding unit associated with the coding technique. In some examples, such as palette mode coding, the mode selection unit 202 may not generate a prediction block, but instead generate syntax elements indicating how to reconstruct the block based on the selected palette. In such a mode, the mode selection unit 202 may provide these syntax elements to the entropy coding unit 220 for encoding.

[0152] As described above, the residual generation unit 204 receives video data of a current block and a corresponding prediction block. The residual generation unit 204 then generates a residual block for the current block. To generate the residual block, the residual generation unit 204 calculates the sample-by-sample difference between the prediction block and the current block.

[0153] The transform processing unit 206 applies one or more transforms to the residual block to generate a block of transform coefficients (referred to herein as a "transform coefficient block"). The transform processing unit 206 may apply various transforms to the residual block to form a transform coefficient block. For example, the transform processing unit 206 may apply a discrete cosine transform (DCT), a directional transform, a Karhunen-Loeve transform (KLT), or a conceptually similar transform to the residual block. In some examples, the transform processing unit 206 may perform multiple transforms on the residual block, such as a primary transform and a secondary transform, such as a rotation transform. In some examples, the transform processing unit 206 does not apply a transform to the residual block.

[0154] When operating in accordance with AV1, the transform processing unit 206 may apply one or more transforms to the residual block to generate a block of transform coefficients (referred to herein as a "transform coefficient block"). The transform processing unit 206 may apply various transforms to the residual block to form a transform coefficient block. For example, the transform processing unit 206 may apply a horizontal / vertical transform combination that may include a discrete cosine transform (DCT), an asymmetric discrete sine transform (ADST), a flipped ADST (e.g., an ADST in reverse order), and an identity transform (IDTX). When the identity transform is used, the transform is skipped in one of the vertical direction or the horizontal direction. In some examples, the transform process may be skipped.

[0155] The quantization unit 208 may quantize the transform coefficients in the transform coefficient block to produce a quantized transform coefficient block. The quantization unit 208 may quantize the transform coefficients of the transform coefficient block according to a quantization parameter (QP) value associated with the current block. The video encoder 200 (e.g., via the mode selection unit 202) may adjust the degree of quantization applied to the transform coefficient block associated with the current block by adjusting the QP value associated with the CU. Quantization may introduce information loss, and therefore, the quantized transform coefficients may have lower precision than the original transform coefficients produced by the transform processing unit 206.

[0156] The inverse quantization unit 210 and the inverse transform processing unit 212 may apply inverse quantization and inverse transform, respectively, to the quantized transform coefficient block to reconstruct a residual block from the transform coefficient block. The reconstruction unit 214 may generate a reconstructed block corresponding to the current block (although possibly with some degree of distortion) based on the reconstructed residual block and the prediction block generated by the mode selection unit 202. For example, the reconstruction unit 214 may add samples of the reconstructed residual block to corresponding samples of the prediction block generated by the mode selection unit 202 to generate a reconstructed block.

[0157] Filter unit 216 may perform one or more filter operations on the reconstructed block. For example, filter unit 216 may perform a deblocking operation to reduce blocking artifacts along the edges of the CU. In some examples, the operations of filter unit 216 may be skipped.

[0158] When operating according to AV1, filter unit 216 may perform one or more filter operations on the reconstructed block. For example, filter unit 216 may perform a deblocking operation to reduce blocking artifacts along the edges of the CU. In other examples, filter unit 216 may apply a constrained directional enhancement filter (CDEF), which may be applied after deblocking and may include applying a non-separable nonlinear low-pass directional filter based on the estimated edge direction. Filter unit 216 may also include a loop recovery filter applied after CDEF, and may include a separable symmetric normalized Wiener filter or a dual self-guided filter.

[0159] The video encoder 200 stores the reconstructed blocks in the DPB 218. For example, in an example where the operation of the filter unit 216 is not performed, the reconstruction unit 214 can store the reconstructed blocks to the DPB 218. In an example where the operation of the filter unit 216 is performed, the filter unit 216 can store the filtered reconstructed blocks to the DPB 218. The motion estimation unit 222 and the motion compensation unit 224 can retrieve a reference picture from the DPB 218, which is formed by the reconstructed (and possibly filtered) blocks, to perform inter-frame prediction on blocks of subsequently encoded pictures. In addition, the intra-frame prediction unit 226 can use the reconstructed blocks in the DPB 218 of the current picture to perform intra-frame prediction on other blocks in the current picture.

[0160] In general, the entropy coding unit 220 may entropy encode syntax elements received from other functional components of the video encoder 200. For example, the entropy coding unit 220 may entropy encode a quantized transform coefficient block from the quantization unit 208. As another example, the entropy coding unit 220 may entropy encode a prediction syntax element (e.g., motion information for inter prediction or intra mode information for intra prediction) from the mode selection unit 202. The entropy coding unit 220 may perform one or more entropy coding operations on the syntax elements (which is another example of video data) to generate entropy-encoded data. For example, the entropy coding unit 220 may perform a context-adaptive variable length coding (CAVLC) operation, a CABAC operation, a variable-to-variable (V2V) length coding operation, a syntax-based context-adaptive binary arithmetic coding (SBAC) operation, a probability interval partitioning entropy (PIPE) coding operation, an exponential Golomb coding operation, or another entropy coding operation on the data. In some examples, entropy encoding unit 220 may operate in a bypass mode in which syntax elements are not entropy encoded.

[0161] The video encoder 200 may output a bitstream including entropy-encoded syntax elements required for reconstructing a block of a slice or picture. In particular, the entropy encoding unit 220 may output a bitstream.

[0162] According to AV1, the entropy coding unit 220 may be configured as a symbol-to-symbol adaptive multi-symbol arithmetic decoder. The syntax elements in AV1 include an alphabet of N elements, and the context (e.g., a probability model) includes a set of N probabilities. The entropy coding unit 220 may store the probabilities as an n-bit (e.g., 15-bit) cumulative distribution function (CDF). The entropy coding unit 220 may perform recursive scaling using an update factor based on the alphabet size to update the context.

[0163] The above operations are described for blocks. Such description should be understood as operations for luma coding blocks and / or chroma coding blocks. As described above, in some examples, the luma coding blocks and chroma coding blocks are the luma components and chroma components of a CU. In some examples, the luma coding blocks and chroma coding blocks are the luma components and chroma components of a PU.

[0164] In some examples, operations performed for luma coding blocks need not be repeated for chroma coding blocks. As an example, operations for identifying motion vectors (MVs) and reference pictures for luma coding blocks need not be repeated in order to identify MVs and reference pictures for chroma blocks. Instead, the MVs for luma coding blocks may be scaled to determine the MVs for chroma blocks, and the reference pictures may be the same. As another example, the intra prediction process may be the same for luma coding blocks and chroma coding blocks.

[0165] Video encoder 200 represents an example of a device configured to encode video data, including: a memory configured to store the video data; and one or more processing units implemented in circuits and configured to generate a fusion of predictors from two or more sample reference rows relative to a block of video data, and encode the block of video data using the fusion of predictors.

[0166] Figure 8 is a block diagram illustrating an example video decoder 300 that can perform the techniques of this disclosure. Figure 8 This is for illustrative purposes only and is not intended to limit the techniques extensively illustrated and described in this disclosure. For illustrative purposes, this disclosure describes a video decoder 300 based on techniques of VVC (ITU-T H.266, under development) and HEVC (ITU-T H.265). However, the techniques of this disclosure may be performed by a video coding device configured for use with other video coding standards.

[0167] exist Figure 8In the example of , the video decoder 300 includes a coded picture buffer (CPB) memory 320, an entropy decoding unit 302, a prediction processing unit 304, an inverse quantization unit 306, an inverse transform processing unit 308, a reconstruction unit 310, a filter unit 312, and a decoded picture buffer (DPB) 314. Any or all of the CPB memory 320, the entropy decoding unit 302, the prediction processing unit 304, the inverse quantization unit 306, the inverse transform processing unit 308, the reconstruction unit 310, the filter unit 312, and the DPB 314 may be implemented in one or more processors or in processing circuits. For example, the units of the video decoder 300 may be implemented as one or more circuits or logic elements as part of a hardware circuit or as part of a processor, ASIC, or FPGA. In addition, the video decoder 300 may include additional or alternative processors or processing circuits to perform these functions and other functions.

[0168] The prediction processing unit 304 includes a motion compensation unit 316 and an intra prediction unit 318. The prediction processing unit 304 may include additional units to perform predictions according to other prediction modes. As an example, the prediction processing unit 304 may include a palette unit, an intra-block copy unit (which may form part of the motion compensation unit 316), an affine unit, a linear model (LM) unit, etc. In other examples, the video decoder 300 may include more, fewer, or different functional components.

[0169] As described above, when operating according to AV1, the motion compensation unit 316 may be configured to decode coding blocks of video data (e.g., both luma coding blocks and chroma coding blocks) using translational motion compensation, affine motion compensation, OBMC, and / or composite inter-intra prediction. As described above, the intra prediction unit 318 may be configured to decode coding blocks of video data (e.g., both luma coding blocks and chroma coding blocks) using directional intra prediction, non-directional intra prediction, recursive filter intra prediction, CFL, intra block copy (IBC), and / or palette mode.

[0170] CPB memory 320 may store video data, such as an encoded video bitstream, to be decoded by components of video decoder 300. For example, video data stored in CPB memory 320 may be obtained from computer-readable medium 110 ( Figure 1). The CPB memory 320 may include a CPB that stores encoded video data (e.g., syntax elements) from an encoded video bitstream. Moreover, the CPB memory 320 may store video data other than syntax elements of decoded pictures, such as temporary data representing outputs from various units of the video decoder 300. The DPB 314 typically stores decoded pictures, and the video decoder 300 may output decoded pictures and / or use decoded pictures as reference video data when decoding subsequent data or pictures of the encoded video bitstream. The CPB memory 320 and the DPB 314 may be formed by any of a variety of storage devices, such as DRAM, including SDRAM, MRAM, RRAM, or other types of storage devices. The CPB memory 320 and the DPB 314 may be provided by the same storage device or a separate storage device. In various examples, the CPB memory 320 may be on-chip with other components of the video decoder 300, or off-chip relative to those components.

[0171] Additionally or alternatively, in some examples, video decoder 300 may retrieve the video from memory 120 ( Figure 1 ) retrieves the decoded video data. That is, memory 120 may store data together with CPB memory 320 as described above. Similarly, when some or all of the functions of video decoder 300 are implemented in software to be performed by the processing circuitry of video decoder 300, memory 120 may store instructions to be executed by video decoder 300.

[0172] Show Figure 8 The various units shown in FIG. 1 and FIG. 2 are provided to help understand the operations performed by the video decoder 300. These units may be implemented as fixed function circuits, programmable circuits, or a combination thereof. Figure 7 , a fixed-function circuit refers to a circuit that provides a specific function and is pre-set to perform executable operations. A programmable circuit refers to a circuit that can be programmed to perform various tasks and provide flexible functions in the executable operations. For example, a programmable circuit can execute software or firmware, which causes the programmable circuit to operate in a manner defined by the instructions of the software or firmware. A fixed-function circuit can execute software instructions (for example, to receive parameters or output parameters), but the type of operation performed by the fixed-function circuit is generally immutable. In some examples, one or more of the units may be different circuit blocks (fixed function or programmable), and in some examples, one or more of the units may be integrated circuits.

[0173] The video decoder 300 may include an ALU, an EFU, a digital circuit, an analog circuit, and / or a programmable core formed by a programmable circuit. In an example where the operation of the video decoder 300 is performed by software executed in a programmable circuit, an on-chip or off-chip memory may store instructions (e.g., object code) of the software received and executed by the video decoder 300.

[0174] Entropy decoding unit 302 may receive encoded video data from the CPB and entropy decode the video data to reproduce syntax elements. Prediction processing unit 304, inverse quantization unit 306, inverse transform processing unit 308, reconstruction unit 310, and filter unit 312 may generate decoded video data based on syntax elements extracted from the bitstream.

[0175] Typically, the video decoder 300 reconstructs a picture on a block-by-block basis. The video decoder 300 may perform a reconstruction operation on each block individually (where the block currently being reconstructed (ie, decoded) may be referred to as a "current block").

[0176] The entropy decoding unit 302 may entropy decode the following: syntax elements defining the quantized transform coefficients in the quantized transform coefficient block, and transform information such as a quantization parameter (QP) and / or a transform mode indication. The inverse quantization unit 306 may use the QP associated with the quantized transform coefficient block to determine a quantization degree, and likewise, determine the inverse quantization degree applied by the inverse quantization unit 306. The inverse quantization unit 306 may, for example, perform a bitwise left shift operation to inverse quantize the quantized transform coefficients. The inverse quantization unit 306 may thereby form a transform coefficient block including the transform coefficients.

[0177] After the inverse quantization unit 306 forms the transform coefficient block, the inverse transform processing unit 308 may apply one or more inverse transforms to the transform coefficient block to generate a residual block associated with the current block. For example, the inverse transform processing unit 308 may apply an inverse DCT, an inverse integer transform, an inverse Karhunen-Loeve transform (KLT), an inverse rotational transform, an inverse directional transform, or another inverse transform to the transform coefficient block.

[0178] In addition, prediction processing unit 304 generates a prediction block based on the prediction information syntax elements entropy decoded by entropy decoding unit 302. For example, if the prediction information syntax elements indicate that the current block is inter-predicted, motion compensation unit 316 can generate the prediction block. In this case, the prediction information syntax elements can indicate a reference picture in DPB 314 from which the reference block is retrieved, and a motion vector that identifies the position of the reference block in the reference picture relative to the position of the current block in the current picture. Motion compensation unit 316 can generally generate a prediction block in the same manner as for motion compensation unit 224 ( Figure 7) is performed in a manner substantially similar to that described herein.

[0179] As another example, if the prediction information syntax element indicates that the current block is intra-predicted, the intra-prediction unit 318 can generate a prediction block according to the intra-prediction mode indicated by the prediction information syntax element. Similarly, the intra-prediction unit 318 can generally generate a prediction block in the same manner as for the intra-prediction unit 226 ( Figure 7 ) The intra prediction unit 318 may retrieve data of neighboring samples of the current block from the DPB 314.

[0180] The intra prediction unit 318 may generate a fusion of predictors from two or more sample reference rows relative to a block of video data based on an intra prediction mode, as described herein. In some examples, the intra prediction unit 318 may generate a fusion of predictors based on a weighted combination of predictors from two or more sample reference rows based on an intra prediction mode. In some examples, the intra prediction unit 318 may select a reference row for a predictor as, for example, a combination of any two intra predictors derived from any two reference rows.

[0181] In some examples, the intra prediction unit 318 may generate a fusion of predictors based on a weighted combination of predictors from two or more intra modes derived from the same reference row but using different intra prediction methods. The intra prediction unit 318 may be configured to generate a fusion of predictors from two or more sample reference rows relative to a block of video data and decode the block of video data using the fusion of predictors and the intra prediction mode. In some examples, the intra prediction unit 318 may apply intra prediction fusion only to modes with non-integer slopes.

[0182] The reconstruction unit 310 may reconstruct the current block using the prediction block and the residual block. For example, the reconstruction unit 310 may add samples of the residual block to corresponding samples of the prediction block to reconstruct the current block.

[0183] The filter unit 312 may perform one or more filter operations on the reconstructed block. For example, the filter unit 312 may perform a deblocking operation to reduce blocking artifacts along the edges of the reconstructed block. The operations of the filter unit 312 may not necessarily be performed in all examples.

[0184] The video decoder 300 may store the reconstructed block in the DPB 314. For example, in an example where the operation of the filter unit 312 is not performed, the reconstruction unit 310 may store the reconstructed block to the DPB 314. In an example where the operation of the filter unit 312 is performed, the filter unit 312 may store the filtered reconstructed block to the DPB 314. As described above, the DPB 314 may provide reference information to the prediction processing unit 304, such as samples of the current picture for intra-frame prediction and previously decoded pictures for subsequent motion compensation. In addition, the video decoder 300 may output a decoded picture (e.g., a decoded video) from the DPB 314 for subsequent display on a display device (e.g., Figure 1 The image is presented on a display device 118).

[0185] In this manner, video decoder 300 represents an example of a video decoding device comprising: a memory configured to store video data; and one or more processing units implemented in circuitry and configured to: generate a fusion of predictors from two or more sample reference rows relative to a block of video data, and decode the block of video data using the fusion of predictors.

[0186] Fig. 9 1 is a flowchart illustrating an example method for encoding a current block according to techniques of the present disclosure. The current block may include CU 130. Although for video encoder 200 ( Figure 1 and 7 ), but it should be understood that other devices may be configured to perform the same Fig. 9 A similar approach to the one used in this paper.

[0187] In this example, the video encoder 200 initially predicts the current block (350). For example, the video encoder 200 may form a prediction block for the current block. The video encoder 200 may then calculate a residual block for the current block (352). To calculate the residual block, the video encoder 200 may calculate the difference between the original uncoded block and the prediction block for the current block. The video encoder 200 may then transform the residual block and quantize the transform coefficients of the residual block (354). Next, the video encoder 200 may scan the quantized transform coefficients of the residual block (356). During or after the scan, the video encoder 200 may entropy encode the transform coefficients (358). For example, the video encoder 200 may encode the transform coefficients using CAVLC or CABAC. The video encoder 200 may then output the entropy encoded data of the block (360).

[0188] Fig.101 is a flowchart illustrating an example method for decoding a current block of video data according to techniques of the present disclosure. The current block may include CU 130. Although for video decoder 300 ( Figure 1 and 8 ), but it should be understood that other devices may be configured to perform the same Fig.10 A similar approach to the one used in this paper.

[0189] The video decoder 300 may receive entropy coded data of a current block, such as entropy coded prediction information corresponding to the current block and entropy coded data of transform coefficients of a residual block (370). The video decoder 300 may entropy decode the entropy coded data to determine the prediction information of the current block and reproduce the transform coefficients of the residual block (372). The video decoder 300 may predict the current block (374), for example, using an intra prediction mode or an inter prediction mode indicated by the prediction information of the current block to calculate a prediction block of the current block. The video decoder 300 may then inverse scan the reproduced transform coefficients (376) to create a block of quantized transform coefficients. The video decoder 300 may then inverse quantize the transform coefficients and apply an inverse transform to the transform coefficients to produce a residual block (378). The video decoder 300 may ultimately decode the current block by combining the prediction block and the residual block (380).

[0190] Fig.11 1 is a flowchart illustrating an example method for encoding a current block according to techniques of the present disclosure. The current block may include CU 130. Although for video encoder 200 ( Figure 1 and 7 ), but it should be understood that other devices may be configured to perform the same Fig.11 A similar approach to the one used in this paper.

[0191] In this example, the video encoder 200 may generate a fusion of predictors from two or more sample reference rows relative to the block of video data based on the intra prediction mode (390). In some examples, the video encoder 200 may generate the fusion of predictors based on a weighted combination of predictors from two or more sample reference rows based on the intra prediction mode. For example, the video encoder 200 may select the reference row of the predictor as a combination of a conventional default reference row (e.g., row 0) and other different reference rows.

[0192] In some examples, the video encoder 200 may determine the predictor from two or more sample reference rows using the same intra prediction mode. In another example, the video encoder 200 may determine the predictor from two or more sample reference rows using at least two different intra prediction modes. The video encoder 200 may apply intra prediction fusion to intra prediction modes with non-integer slopes.

[0193] The video encoder 200 may select reference rows as a subset of rows used in MRL prediction. In some examples, the subset of the sample reference row set includes: a default sample reference row adjacent to the video data block, and other sample reference rows adjacent to the default sample reference row. In some examples, the video encoder 200 may select the other reference rows as reference rows that are a certain distance from the conventional default reference rows. In some examples, the video encoder 200 may specifically select the other reference rows as rows that are not used in MRL prediction to provide diversity. For example, the other reference rows may be rows 2 and 4, which are not used in the current MRL mode. In another example, the other reference rows may also be a mixture of reference rows used in MRL and not used in MRL.

[0194] In one example, the video encoder 200 can achieve fusion of two or more intra-frame predictors by determining a weighted combination of predictors from multiple reference rows. For example, the video encoder 200 may apply a first weight to the predictors in the default reference row and a second weight to the predictors in the other reference rows. In one example, the weight of each predictor may be fixed. For example, the video encoder 200 may determine that the first weight is 0.75 and the second weight is 0.25. In another example, the video encoder 200 may determine the weight based on the position of the current sample in the block and one or more of the width or height of the block. In yet another example, the video encoder 200 may determine the weight based on certain criteria, such as whether the absolute value of the first predictor minus the second predictor meets a threshold (e.g., is greater than or equal to a threshold).

[0195] The video encoder 200 may apply one or more interpolation filters to a block of video data. The video encoder 200 may derive prediction samples from reference samples after interpolation with any type of filter (e.g., a 6-tap filter or a 4-tap filter). In some examples, the video encoder 200 may derive prediction samples from a mixture of different types of filters. For example, the video encoder 200 may derive one prediction sample from a 6-tap interpolation filter and another prediction sample from a 4-tap interpolation filter.

[0196] The video encoder 200 may filter the fusion of the predictors using a two-dimensional (2D) filter, such as a low-pass filter, a high-pass filter, etc., to generate one or more prediction samples. For example, the video encoder 200 may use multiple reference lines as inputs to the 2D filter to generate prediction samples. In one example, the 2D filter may represent an interpolation or smoothing applied to the reference sample and the disclosed intra-frame prediction fusion to generate an intra-frame predictor. For example, the 2D filter may be a 2 by 3 low-pass filter. In another example, the 2D filter may be a 3 by 3 high-pass filter. The video encoder 200 may use one or more prediction samples to decode a block of video data.

[0197] In any case, the video encoder 300 can encode the block of video data using a fusion of predictors and the intra-prediction mode (392). In this way, the technique can improve intra-prediction and thereby improve compression efficiency, visual quality, etc.

[0198] Fig.12 1 is a flowchart illustrating an example method for decoding a current block of video data according to techniques of the present disclosure. The current block may include CU 130. Although for video decoder 300 ( Figure 1 and 8 ), but it should be understood that other devices may be configured to perform the same Fig.12 A similar approach to the one used in this paper.

[0199] In this example, the video decoder 300 may generate a fusion of predictors from two or more sample reference rows relative to a block of video data based on an intra prediction mode (400). In some examples, the video decoder 300 may generate the fusion of predictors based on a weighted combination of predictors from two or more sample reference rows based on the intra prediction mode. For example, the video decoder 300 may select the reference row for the predictor as a combination of a conventional default reference row (e.g., row 0) and other different reference rows.

[0200] In some examples, the video decoder 300 may determine the predictor from two or more sample reference rows using the same intra prediction mode. In another example, the video decoder 300 may determine the predictor from two or more sample reference rows using at least two different intra prediction modes. The video decoder 300 may apply intra prediction fusion to intra prediction modes with non-integer slopes.

[0201] The video decoder 300 may select reference rows as a subset of rows used in MRL prediction. In some examples, the subset of the sample reference row set includes: a default sample reference row adjacent to the video data block, and other sample reference rows adjacent to the default sample reference row. In some examples, the video decoder 300 may select the other reference rows as reference rows that are a certain distance from the conventional default reference rows. In some examples, the video decoder 300 may specifically select the other reference rows as rows that are not used in MRL prediction to provide diversity. For example, the other reference rows may be rows 2 and 4, which are not used in the current MRL mode. In another example, the other reference rows may also be a mixture of reference rows used in MRL and not used in MRL.

[0202] In one example, the video decoder 300 can achieve the fusion of two or more intra-frame predictors by determining a weighted combination of predictors from multiple reference rows. For example, the video decoder 300 can apply a first weight to the predictors in the default reference row and a second weight to the predictors in other reference rows. In one example, the weight of each predictor can be fixed. For example, the video decoder 300 can determine that the first weight is 0.75 and the second weight is 0.25. In another example, the video decoder 300 can determine the weight based on the position of the current sample in the block and one or more of the width or height of the block. In yet another example, the video decoder 300 can determine the weight based on certain criteria, such as whether the absolute value of the first predictor minus the second predictor meets a threshold.

[0203] The video decoder 300 may apply one or more interpolation filters to a block of video data. The video decoder 300 may derive prediction samples from reference samples after interpolation with any type of filter (e.g., a 6-tap filter or a 4-tap filter). In some examples, the video decoder 300 may derive prediction samples from a mixture of different types of filters. For example, the video decoder 300 may derive one prediction sample from a 6-tap interpolation filter and another prediction sample from a 4-tap interpolation filter.

[0204] The video decoder 300 may filter the fusion of the predictors using a two-dimensional (2D) filter, such as a low-pass filter, a high-pass filter, etc., to generate one or more prediction samples. For example, the video decoder 300 may use multiple reference lines as inputs to the 2D filter to generate prediction samples. In one example, the 2D filter may represent an interpolation or smoothing applied to the reference sample and the disclosed intra-frame prediction fusion to generate an intra-frame predictor. For example, the 2D filter may be a 2 by 3 low-pass filter. In another example, the 2D filter may be a 3 by 3 high-pass filter. The video decoder 300 may decode the video data block using one or more prediction samples.

[0205] In any case, the video decoder 300 may decode the block of video data using a fusion of predictors and the intra prediction mode (402). In this way, the technique may improve intra prediction and thereby improve compression efficiency, visual quality, and the like.

[0206] Other illustrative aspects of the disclosure are described below.

[0207] Aspect 1A - A method of coding video data, the method comprising: generating a fusion of predictors from two or more sample reference rows relative to a block of video data; and coding the block of video data using the fusion of predictors.

[0208] Aspect 2A—The method of aspect 1A, wherein the two or more sample reference rows include a default sample reference row.

[0209] Aspect 3A—The method of aspect 2A, wherein the default sample reference row is immediately adjacent to the video data block.

[0210] Aspect 4A-The method according to aspect 1A, further comprising: determining the predictor from the two or more sample reference rows using the same intra-frame prediction mode.

[0211] Aspect 5A-The method according to aspect 1A, further comprising: determining the predictor from the two or more sample reference rows using at least two different intra-frame prediction modes.

[0212] Aspect 6A - The method of aspect 1A, wherein the two or more sample reference rows are a subset of a set of sample reference rows for a multiple reference row coding mode.

[0213] Aspect 7A - The method according to aspect 6A, wherein the set of sample reference rows for multi-reference row decoding mode includes row 0, row 1, row 3, row 5, row 7 and row 12 relative to the video data block.

[0214] Aspect 8A—The method according to Aspect 7A, wherein the subset of the sample reference row set includes row 0 and row 1.

[0215] Aspect 9A—A method according to Aspect 7A, wherein the subset of the sample reference row set includes row 0, row 3 and row 5.

[0216] Aspect 10A—The method according to Aspect 7A, wherein the subset of the sample reference row set includes row 3 and row 5.

[0217] Aspect 11A-The method according to aspect 1A further comprises: determining at least one of the two or more sample reference rows based on distances of samples of a default sample reference row.

[0218] Aspect 12A - The method of aspect 1A, wherein at least one of the two or more sample reference rows is not in a set of sample reference rows for a multiple reference row coding mode.

[0219] Aspect 13A—A method according to aspect 1A, wherein generating the fusion of the predictors from two or more sample reference rows relative to the video data block includes: generating the fusion of the predictors based on a weighted combination of the predictors from the two or more sample reference rows.

[0220] Aspect 14A-The method according to Aspect 13A, wherein the weights of the weighted combination are fixed.

[0221] Aspect 15A—The method of aspect 13A, wherein the weights of the weighted combination are based on a reference row.

[0222] Clause 16A—The method of Clause 13A, wherein the weights of the weighted combination are based on the positions of the samples in the block of video data.

[0223] Aspect 17A—The method of aspect 13A, wherein the weight of the weighted combination is based on a distance between two reference rows of the two or more sample reference rows.

[0224] Aspect 18A—The method of aspect 13A, wherein the weights of the weighted combination are based on a cost criterion.

[0225] Aspect 19A—A method according to aspect 1A, wherein generating a fusion of the predictors from two or more sample reference rows relative to a block of video data comprises generating a fusion of the predictors based on weighted gradients of the predictors from the two or more sample reference rows.

[0226] Aspect 20A-The method of aspect 1A, further comprising: determining to generate the blend of predictors based on one or more of an intra prediction mode or syntax elements received in an encoded video bitstream.

[0227] Aspect 21A-The method according to aspect 1A further comprises: in addition to generating the fusion of predictors, performing one or more of a template-based intra-frame mode derivation mode or a decoder-side intra-frame mode derivation mode.

[0228] Aspect 22A-A method according to any of aspects 1A-21A, wherein decoding includes decoding.

[0229] Aspect 23A-A method according to any of Aspects 1A-21A, wherein decoding includes encoding.

[0230] Aspect 24A - An apparatus for decoding video data, the apparatus comprising one or more means for performing the method of any of Aspects 1A-23A.

[0231] Aspect 25A - The apparatus of aspect 24A, wherein the one or more units include one or more processors implemented in circuitry.

[0232] Aspect 26A-The apparatus according to any of Aspects 24A and 25A, further comprising: a memory for storing the video data.

[0233] Aspect 27A - The apparatus of any of Aspects 24A-26A, further comprising: a display configured to display the decoded video data.

[0234] Aspect 28A—A device according to any of Aspects 24A-27A, wherein the device includes one or more of a camera, a computer, a mobile device, a broadcast receiver device, or a set-top box.

[0235] Aspect 29A - An apparatus according to any of Aspects 24A-28A, wherein the apparatus comprises a video decoder.

[0236] Aspect 30A—The apparatus of any of Aspects 24A-29A, wherein the apparatus comprises a video encoder.

[0237] Aspect 31A - A computer-readable storage medium having stored thereon instructions which, when executed, cause one or more processors to perform a method according to any one of aspects 1A-23A.

[0238] Aspect 1B: A method of decoding video data comprises: generating a fusion of predictors from two or more sample reference rows relative to a block of video data based on an intra-frame prediction mode; and decoding the block of video data using the fusion of predictors and the intra-frame prediction mode.

[0239] Aspect 2B: The method according to aspect 1B, wherein the intra-frame prediction mode has a non-integer slope.

[0240] Aspect 3B: A method according to any one of Aspects 1B and 2B, wherein generating a fusion of predictors from two or more sample reference rows relative to a video data block based on an intra-frame prediction mode includes: generating a fusion of the predictors based on a weighted combination of the predictors from the two or more sample reference rows based on the intra-frame prediction mode.

[0241] Aspect 4B: A method according to aspect 3B, wherein, based on the intra-frame prediction mode, generating a fusion of the predictors based on a weighted combination of the predictors from the two or more sample reference rows includes: applying a first weight to a first predictor in a first reference row of the two or more sample reference rows; and applying a second weight to a second predictor in a second reference row of the two or more sample reference rows, wherein the first reference row is closer to the video data block than the second reference row.

[0242] Aspect 5B: The method according to aspect 4B, wherein the first weight is 0.75 and the second weight is 0.25.

[0243] Aspect 6B: A method according to any one of Aspects 4B and 5B, wherein the method further includes: in response to the absolute value of the first predictor minus the second predictor being greater than or equal to a threshold, determining that the first weight is 0.75 and the second weight is 0.25; and in response to the absolute value of the first predictor minus the second predictor being less than the threshold, determining that the first weight is 0.5 and the second weight is 0.5.

[0244] Aspect 7B: A method according to any one of Aspects 4B-6B, wherein the method further includes: determining the first weight based on the position of the sample in the block and one or more of the width or height of the block; and determining the second weight based on the position of the sample and one or more of the width or the height of the block.

[0245] Aspect 8B: A method according to any one of Aspects 1B-7B, wherein generating the fusion of the predictors includes: filtering the two or more sample reference rows using one of a low-pass filter or a high-pass filter to generate one or more prediction samples, and wherein decoding the video data block includes decoding the video data block using the one or more prediction samples.

[0246] Aspect 9B: The method according to any one of aspects 1B-8B, wherein generating the fusion of predictors is in response to intra-frame sub-division mode being disabled.

[0247] Aspect 10B: A method according to any one of aspects 1B-9B, wherein the method further comprises: determining the predictor from the two or more sample reference rows using at least two different intra-frame prediction modes, wherein the at least two different intra-frame prediction modes are angular modes.

[0248] Aspect 11B: The method according to any of aspects 1B-10B, wherein the two or more sample reference rows include a first reference row from a set of reference sample rows for a multiple reference row decoding mode.

[0249] Aspect 12B: The method according to aspect 11B, wherein the two or more sample reference rows further include a second sample reference row adjacent to and above the first sample reference row.

[0250] Aspect 13B: An apparatus configured to decode video data comprises: a memory configured to store a block of video data; and one or more processors implemented in circuitry and in communication with the memory, the one or more processors configured to: generate a fusion of predictors from two or more sample reference rows relative to the block of video data based on an intra-frame prediction mode; and decode the block of video data using the fusion of predictors and the intra-frame prediction mode.

[0251] Aspect 14B: The apparatus of aspect 13B, wherein the intra prediction mode has a non-integer slope.

[0252] Aspect 15B: An apparatus according to any one of Aspects 13B and 14B, wherein, in order to generate a fusion of the predictors from the two or more sample reference rows relative to the video data block based on the intra-frame prediction mode, the one or more processors are also configured to: generate a fusion of the predictors based on a weighted combination of the predictors from the two or more sample reference rows based on the intra-frame prediction mode.

[0253] Aspect 16B: An apparatus according to Aspect 15B, wherein, in order to generate a fusion of the predictors based on a weighted combination of predictors from the two or more sample reference rows based on the intra-frame prediction mode, the one or more processors are also configured to: apply a first weight to a first predictor in a first reference row of the two or more sample reference rows; and apply a second weight to a second predictor in a second reference row of the two or more sample reference rows, wherein the first reference row is closer to the video data block than the second reference row.

[0254] Aspect 17B: The apparatus of aspect 16B, wherein the first weight is 0.75 and the second weight is 0.25.

[0255] Aspect 18B: An apparatus according to any one of Aspects 16B and 17B, wherein the one or more processors are further configured to: determine that the first weight is 0.75 and the second weight is 0.25 in response to the absolute value of the first predictor minus the second predictor being greater than or equal to a threshold; and determine that the first weight is 0.5 and the second weight is 0.5 in response to the absolute value of the first predictor minus the second predictor being less than the threshold.

[0256] Aspect 19B: An apparatus according to any one of Aspects 16B-18B, wherein the one or more processors are further configured to: determine the first weight based on the position of the sample in the block and one or more of the width or height of the block; and determine the second weight based on the position of the sample and one or more of the width or height of the block.

[0257] Aspect 20B: An apparatus according to any one of Aspects 13B-19B, wherein, in order to generate a fusion of the predictors, the one or more processors are further configured to: filter the two or more reference lines using one of a low-pass filter or a high-pass filter to generate one or more prediction samples, and wherein, in order to decode the video data block, the one or more processors are further configured to: decode the video data block using the one or more prediction samples.

[0258] Aspect 21B: An apparatus according to any one of aspects 13B-20B, wherein the one or more processors are configured to: generate the fusion of the predictors in response to the intra-frame sub-partitioning mode being disabled.

[0259] Aspect 22B: An apparatus according to any one of Aspects 13B-21B, wherein the one or more processors are further configured to: determine the predictor from the two or more sample reference rows using at least two different intra-frame prediction modes, wherein the at least two different intra-frame prediction modes are angular modes.

[0260] Aspect 23B: The apparatus of any of aspects 13B-22B, wherein the two or more sample reference rows comprise a first reference row from a set of sample reference rows for a multiple reference row coding mode.

[0261] Aspect 24B: The apparatus of aspect 23B, wherein the two or more sample reference rows further include a second sample reference row adjacent to and above the first sample reference row.

[0262] Aspect 25B: A method of encoding video data, comprising: generating a fusion of predictors from two or more sample reference rows relative to a block of video data based on an intra-frame prediction mode; and encoding the block of video data using the fusion of predictors and the intra-frame prediction mode.

[0263] Aspect 26B: The method of aspect 25B, wherein the intra prediction mode has a non-integer slope.

[0264] Aspect 27B: A method according to any one of Aspects 25B and 26B, wherein generating the fusion of the predictors from the two or more sample reference rows relative to the video data block based on the intra-frame prediction mode includes: generating the fusion of the predictors based on a weighted combination of the predictors from the two or more sample reference rows based on the intra-frame prediction mode.

[0265] Aspect 28B: A method according to aspect 27B, wherein, based on the intra-frame prediction mode, generating a fusion of the predictors based on a weighted combination of the predictors from the two or more sample reference rows includes: applying a first weight to a first predictor in a first reference row of the two or more sample reference rows; and applying a second weight to a second predictor in a second reference row of the two or more sample reference rows, wherein the first reference row is closer to the video data block than the second reference row.

[0266] Aspect 29B: The method according to Aspect 28B, wherein the first weight is 0.75 and the second weight is 0.25.

[0267] Aspect 30B: A method according to any one of Aspects 28B and 29B, wherein the method further includes: in response to the absolute value of the first predictor minus the second predictor being greater than or equal to a threshold, determining that the first weight is 0.75 and the second weight is 0.25; and in response to the absolute value of the first predictor minus the second predictor being less than the threshold, determining that the first weight is 0.5 and the second weight is 0.5.

[0268] Aspect 31B: A method according to any one of Aspects 28B-30B, wherein the method further includes: determining the first weight based on the position of the sample in the block and one or more of the width or the height of the block; and determining the second weight based on the position of the sample and one or more of the width or the height of the block.

[0269] Aspect 32B: A method according to any one of Aspects 25B-31B, wherein generating the fusion of the predictors includes: filtering the two or more reference rows using one of a low-pass filter or a high-pass filter to generate one or more prediction samples, and wherein encoding the video data block includes encoding the video data block using the one or more prediction samples.

[0270] Aspect 33B: The method according to any one of aspects 25B-32B, wherein generating the fusion of predictors is in response to intra-frame sub-division mode being disabled.

[0271] Aspect 34B: A method according to any one of aspects 25B-33B, wherein the method further comprises: determining the predictor from the two or more sample reference rows using at least two different intra-frame prediction modes, wherein the at least two different intra-frame prediction modes are angular modes.

[0272] Aspect 35B: The method of any of aspects 25B-34B, wherein the two or more sample reference rows comprise a first reference row from a set of reference sample rows for a multiple reference row decoding mode.

[0273] Aspect 36B: The method of aspect 35B, wherein the two or more sample reference rows further include a second sample reference row adjacent to and above the first sample reference row.

[0274] Aspect 37B: An apparatus configured to encode video data, comprising: a memory configured to store a block of video data; and one or more processors implemented in circuitry and in communication with the memory, the one or more processors configured to: generate a fusion of predictors from two or more sample reference rows relative to the block of video data based on an intra-frame prediction mode, and encode the block of video data using the fusion of predictors and the intra-frame prediction mode.

[0275] Aspect 38B: The apparatus of aspect 37B, wherein the intra prediction mode has a non-integer slope.

[0276] Aspect 39B: An apparatus according to any one of Aspects 37B and 38B, wherein, in order to generate the fusion of the predictors from the two or more sample reference rows relative to the video data block based on the intra-frame prediction mode, the one or more processors are also configured to: generate the fusion of the predictors based on a weighted combination of the predictors from the two or more sample reference rows based on the intra-frame prediction mode.

[0277] Aspect 40B: An apparatus according to Aspect 39B, wherein, in order to generate a fusion of the predictors based on a weighted combination of the predictors from the two or more sample reference rows based on the intra-frame prediction mode, the one or more processors are also configured to: apply a first weight to a first predictor in a first reference row of the two or more sample reference rows; and apply a second weight to a second predictor in a second reference row of the two or more sample reference rows, wherein the first reference row is closer to the video data block than the second reference row.

[0278] Aspect 41B: The apparatus according to Aspect 40B, wherein the first weight is 0.75 and the second weight is 0.25.

[0279] Aspect 42B: An apparatus according to any one of Aspects 40B and 41B, wherein the one or more processors are further configured to: determine that the first weight is 0.75 and the second weight is 0.25 in response to the absolute value of the first predictor minus the second predictor being greater than or equal to a threshold; and determine that the first weight is 0.5 and the second weight is 0.5 in response to the absolute value of the first predictor minus the second predictor being less than the threshold.

[0280] Aspect 43B: An apparatus according to any one of Aspects 40B-42B, wherein the one or more processors are further configured to: determine the first weight based on the position of the sample in the block and one or more of the width or height of the block; and determine the second weight based on the position of the sample and one or more of the width or the height of the block.

[0281] Aspect 44B: An apparatus according to any one of Aspects 37B-43B, wherein, in order to generate a fusion of the predictors, the one or more processors are further configured to: filter the two or more sample reference rows using one of a low-pass filter or a high-pass filter to generate one or more prediction samples, and wherein, in order to decode the video data block, the one or more processors are further configured to use the one or more prediction samples to decode the video data block.

[0282] Aspect 45B: An apparatus according to any one of aspects 37B-44B, wherein the one or more processors are configured to: generate the fusion of the predictors in response to the intra-frame sub-partitioning mode being disabled.

[0283] Aspect 46B: An apparatus according to any one of Aspects 37B-45B, wherein the one or more processors are further configured to: determine the predictor from the two or more sample reference rows using at least two different intra-frame prediction modes, wherein the at least two different intra-frame prediction modes are angular modes.

[0284] Aspect 47B: An apparatus according to any of aspects 37B-46B, wherein the two or more sample reference rows include a first reference row from a set of reference sample rows for a multiple reference row decoding mode.

[0285] Aspect 48B: The apparatus of aspect 47B, wherein the two or more sample reference rows further comprise a second sample reference row adjacent to and above the first sample reference row.

[0286] It should be appreciated that, according to examples, certain operations or events of any of the techniques described herein may be performed in a different order, may be added, combined, or omitted entirely (e.g., not all described operations or events are required to implement the technique). In addition, in some examples, operations or events may be performed concurrently rather than sequentially, such as through multithreading, interrupt handling, or multiple processors.

[0287] In one or more exemplary designs, the described functions may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored or sent as one or more instructions or codes on a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media include computer storage media, which correspond to tangible media such as data storage media, or communication media, including, for example, any media that facilitates the transfer of a computer program from one place to another according to a communication protocol. In this manner, computer-readable media may generally correspond to (1) a non-temporary tangible computer-readable storage medium, or (2) a communication medium such as a signal or carrier wave. Data storage media may be any available media that can be accessed by one or more computers or one or more processors to retrieve instructions, codes, and / or data structures to implement the techniques described in the present disclosure. A computer program product may include a computer-readable medium.

[0288] For example, but not limited to, such computer-readable storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage devices, magnetic disk storage devices or other magnetic storage devices, flash memory or any other medium that can be used to store the required program code in the form of instructions or data structures and can be accessed by a computer. In addition, any connection can be appropriately referred to as a computer-readable medium. For example, if the software is sent from a website, server or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technologies such as infrared, wireless and microwaves, the coaxial cable, fiber optic cable, twisted pair, DSL or wireless technologies such as infrared, wireless and microwaves are also included in the definition of the medium. However, it should be understood that computer-readable storage media and data storage media do not include connections, carrier waves, signals or other temporary media, but are directed to non-temporary tangible storage media. The disks and optical disks used herein include compact disks (CDs), laser optical disks, optical optical disks, digital versatile disks (DVDs), floppy disks and blue-ray disks, wherein the disks usually reproduce data magnetically, and the optical disks usually reproduce data optically using lasers. The above combination is also included in the scope of computer-readable media.

[0289] The instructions may be executed by one or more processors, such as one or more DSPs, general-purpose microprocessors, ASICs, FPGAs, or other equivalent integrated or discrete logic circuits. Accordingly, the terms "processor" and "processing circuitry" as used herein may refer to any of the foregoing structures or any other structure suitable for implementing the techniques described herein. In addition, in some aspects, the functionality described herein may be provided within dedicated hardware and / or software modules configured for encoding and decoding, or incorporated in a combined codec. Similarly, the technology may be fully implemented in one or more circuits or logic elements.

[0290] The techniques of the present disclosure may be implemented in a variety of devices or apparatuses including wireless handsets, integrated circuits (ICs), or a set of ICs (e.g., chipsets). Various components, modules, or units are described in the present disclosure to emphasize the functional aspects of devices configured to perform the disclosed techniques, but do not necessarily need to be implemented by different hardware units. Instead, as described above, the various units may be combined in a codec hardware unit, or provided by a collection of interoperable hardware units, including one or more processors as described above in combination with appropriate software and / or firmware.

[0291] Various examples have been described. These and other examples are within the scope of the following claims.

Claims

1. A method for decoding video data, the method comprising: generating a fusion of predictors from two or more reference rows of samples relative to a block of video data based on an intra prediction mode; as well as The block of video data is decoded using the fusion of the predictors and the intra prediction mode.

2. The method according to claim 1, wherein: The intra prediction mode has a non-integer slope.

3. The method according to claim 1, wherein: Generating the fusion of the predictors from the two or more sample reference rows relative to the block of video data based on the intra prediction mode comprises: Based on the intra prediction mode, a fusion of the predictors is generated based on a weighted combination of the predictors from the two or more sample reference rows.

4. The method according to claim 3, wherein: Generating a fusion of the predictors based on the weighted combination of the predictors from the two or more sample reference rows based on the intra prediction mode comprises: applying a first weight to a first predictor in a first reference row of the two or more sample reference rows; and A second weight is applied to a second predictor in a second reference row of the two or more sample reference rows, wherein the first reference row is closer to the block of video data than the second reference row.

5. The method according to claim 4, wherein: The first weight is 0.75 and the second weight is 0.

25.

6. The method according to claim 4, further comprising: In response to an absolute value of the first predictor minus the second predictor being greater than or equal to a threshold, determining that the first weight is 0.75 and the second weight is 0.25; as well as In response to the absolute value of the first predictor minus the second predictor being less than the threshold, determining that the first weight is 0.5 and the second weight is 0.

5.

7. The method according to claim 4, further comprising: determining the first weight based on a position of a sample in the block and one or more of a width or a height of the block; as well as The second weight is determined based on the position of the sample and one or more of the width or the height of the block.

8. The method according to claim 1, wherein: The fusion that generates the predictor includes: filtering the two or more sample reference rows using one of a low pass filter or a high pass filter to generate one or more prediction samples, and The decoding of the video data block includes decoding the video data block using the one or more prediction samples.

9. The method according to claim 1, wherein: Generating the fusion of predictors is responsive to the intra sub-division mode being disabled.

10. The method according to claim 1, further comprising: The predictor is determined from the two or more sample reference rows using at least two different intra prediction modes, wherein the at least two different intra prediction modes are angular modes.

11. The method according to claim 1, wherein: The two or more sample reference rows include a first reference row from a set of sample reference rows for a multiple reference row coding mode.

12. The method according to claim 11, wherein: The two or more sample reference rows also include a second sample reference row adjacent to and above the first sample reference row.

13. An apparatus configured to decode video data, the apparatus comprising: a memory configured to store video data blocks; as well as one or more processors implemented in circuitry and in communication with the memory, the one or more processors being configured to: generating a fusion of predictors from two or more reference rows of samples relative to a block of video data based on an intra prediction mode; as well as The block of video data is decoded using the fusion of the predictors and the intra prediction mode.

14. The device according to claim 13, wherein: The intra prediction mode has a non-integer slope.

15. The device according to claim 13, wherein: To generate the fusion of the predictors from the two or more sample reference rows relative to the block of video data based on the intra prediction mode, the one or more processors are further configured to: Based on the intra prediction mode, a fusion of the predictors is generated based on a weighted combination of the predictors from the two or more sample reference rows.

16. The device according to claim 15, wherein: To generate a fusion of the predictors based on the weighted combination of the predictors from the two or more sample reference rows based on the intra prediction mode, the one or more processors are further configured to: applying a first weight to a first predictor in a first reference row of the two or more sample reference rows; as well as A second weight is applied to a second predictor in a second reference row of the two or more sample reference rows, wherein the first reference row is closer to the block of video data than the second reference row.

17. The device according to claim 16, wherein: The first weight is 0.75 and the second weight is 0.

25.

18. The device according to claim 16, wherein: The one or more processors are further configured to: In response to an absolute value of the first predictor minus the second predictor being greater than or equal to a threshold, determining that the first weight is 0.75 and the second weight is 0.25; and In response to the absolute value of the first predictor minus the second predictor being less than the threshold, determining that the first weight is 0.5 and the second weight is 0.

5.

19. The device according to claim 16, wherein: The one or more processors are further configured to: determining the first weight based on a location of a sample in the block and one or more of a width or a height of the block; and The second weight is determined based on the position of the sample and one or more of the width or the height of the block.

20. The device according to claim 13, wherein: To generate the fusion of predictors, the one or more processors are further configured to: filtering the two or more reference lines using one of a low pass filter or a high pass filter to generate one or more prediction samples, and In order to decode the video data block, the one or more processors are further configured to decode the video data block using the one or more prediction samples.

21. The device according to claim 13, wherein: The one or more processors are configured to: In response to the intra sub-partitioning mode being disabled, generating a fusion of the predictors.

22. The device according to claim 13, wherein: The one or more processors are further configured to: The predictor is determined from the two or more sample reference rows using at least two different intra prediction modes, wherein the at least two different intra prediction modes are angular modes.

23. The device according to claim 13, wherein: The two or more sample reference rows include a first reference row from a set of sample reference rows for a multiple reference row coding mode.

24. The device according to claim 23, wherein: The two or more sample reference rows also include a second sample reference row adjacent to and above the first sample reference row.

25. A method for encoding video data, the method comprising: generating a fusion of predictors from two or more reference rows of samples relative to a block of video data based on an intra prediction mode; as well as The block of video data is encoded using the fusion of the predictors and the intra prediction mode.

26. The method according to claim 25, wherein: The intra prediction mode has a non-integer slope.

27. The method according to claim 25, wherein: Generating the fusion of the predictors from the two or more sample reference rows relative to the block of video data based on the intra prediction mode comprises: Based on the intra prediction mode, a fusion of the predictors is generated based on a weighted combination of the predictors from the two or more sample reference rows.

28. The method according to claim 27, wherein: Generating a fusion of the predictors based on the weighted combination of the predictors from the two or more sample reference rows based on the intra prediction mode comprises: applying a first weight to a first predictor in a first reference row of the two or more sample reference rows; and A second weight is applied to a second predictor in a second reference row of the two or more sample reference rows, wherein the first reference row is closer to the block of video data than the second reference row.

29. The method according to claim 28, wherein: The first weight is 0.75 and the second weight is 0.

25.

30. The method of claim 28, further comprising: In response to an absolute value of the first predictor minus the second predictor being greater than or equal to a threshold, determining that the first weight is 0.75 and the second weight is 0.25; as well as In response to the absolute value of the first predictor minus the second predictor being less than the threshold, determining that the first weight is 0.5 and the second weight is 0.

5.

31. The method of claim 28, further comprising: determining the first weight based on a position of a sample in the block and one or more of a width or a height of the block; as well as The second weight is determined based on the position of the sample and one or more of the width or the height of the block.

32. The method of claim 25, wherein: The fusion that generates the predictor includes: filtering the two or more reference lines using one of a low pass filter or a high pass filter to generate one or more prediction samples, and The encoding of the video data block includes encoding the video data block using the one or more prediction samples.

33. The method of claim 25, wherein: Generating the fusion of predictors is responsive to the intra sub-division mode being disabled.

34. The method of claim 25, further comprising: The predictor is determined from the two or more sample reference rows using at least two different intra prediction modes, wherein the at least two different intra prediction modes are angular modes.

35. The method of claim 25, wherein: The two or more sample reference rows include a first reference row from a set of sample reference rows for a multiple reference row coding mode.

36. The method of claim 35, wherein: The two or more sample reference rows also include a second sample reference row adjacent to and above the first sample reference row.

37. An apparatus configured to encode video data, the apparatus comprising: a memory configured to store video data blocks; as well as one or more processors implemented in circuitry and in communication with the memory, the one or more processors being configured to: generating a fusion of predictors from two or more reference rows of samples relative to the block of video data based on an intra prediction mode, and The block of video data is encoded using the fusion of the predictors and the intra prediction mode.

38. The device according to claim 37, wherein The intra prediction mode has a non-integer slope.

39. The device according to claim 37, wherein: To generate the fusion of the predictors from the two or more sample reference rows relative to the block of video data based on the intra prediction mode, the one or more processors are further configured to: Based on the intra prediction mode, a fusion of the predictors is generated based on a weighted combination of the predictors from the two or more sample reference rows.

40. The device according to claim 39, wherein To generate a fusion of the predictors based on the weighted combination of the predictors from the two or more sample reference rows based on the intra prediction mode, the one or more processors are further configured to: applying a first weight to a first predictor in a first reference row of the two or more sample reference rows; as well as A second weight is applied to a second predictor in a second reference row of the two or more sample reference rows, wherein the first reference row is closer to the block of video data than the second reference row.

41. The device according to claim 40, wherein The first weight is 0.75 and the second weight is 0.

25.

42. The device according to claim 40, wherein: The one or more processors are further configured to: In response to an absolute value of the first predictor minus the second predictor being greater than or equal to a threshold, determining that the first weight is 0.75 and the second weight is 0.25; and In response to the absolute value of the first predictor minus the second predictor being less than the threshold, determining that the first weight is 0.5 and the second weight is 0.

5.

43. The device according to claim 40, wherein: The one or more processors are further configured to: determining the first weight based on a location of a sample in the block and one or more of a width or a height of the block; and The second weight is determined based on the position of the sample and one or more of the width or the height of the block.

44. The apparatus of claim 37, wherein: To generate the fusion of predictors, the one or more processors are further configured to: filtering the two or more reference lines using one of a low pass filter or a high pass filter to generate one or more prediction samples, and In order to decode the video data block, the one or more processors are further configured to use the one or more prediction samples to decode the video data block.

45. The apparatus of claim 37, wherein: The one or more processors are configured to: In response to the intra sub-partitioning mode being disabled, generating a fusion of the predictors.

46. ​​The apparatus of claim 37, wherein: The one or more processors are further configured to: The predictor is determined from the two or more sample reference rows using at least two different intra prediction modes, wherein the at least two different intra prediction modes are angular modes.

47. The apparatus of claim 37, wherein: The two or more sample reference rows include a first reference row from a set of sample reference rows for a multiple reference row coding mode.

48. The apparatus of claim 47, wherein: The two or more sample reference rows also include a second sample reference row adjacent to and above the first sample reference row.

Images