KR20230125781A - Highest Probability Modes for Intra Prediction for Video Coding - Google Patents

Abstract

A video coder may code a block of video data using an intra prediction mode determined from the MPM list. A video coder may construct a generic MPM list containing N entries, where the N entries of the generic MPM list are intra prediction modes, the plane mode is the ordinal first entry in the generic MPM list, and A primary MPM list may be constructed from the first Np entries of , where Np is less than N, and a secondary MPM list may be constructed from the remaining (N-Np) entries in the general MPM list. And the video coder may determine the current intra prediction mode for the current block of video data using the primary MPM list or the secondary MPM list.

Description

Highest Probability Modes for Intra Prediction for Video Coding

This application claims priority to U.S. Application Serial No. 17/456,080, filed on November 22, 2021, and U.S. Provisional Patent Application No. 63/131,115, filed on December 28, 2020, the entire contents of each of which are incorporated herein by reference. U.S. Application Serial No. 17/456,080, filed on November 22, 2021, claims the benefit of U.S. Provisional Patent Application No. 63/131,115, filed on December 28, 2020.

This disclosure relates to video encoding and video decoding.

Digital video capabilities include digital televisions, digital direct broadcast systems, wireless broadcast systems, personal digital assistants (PDAs), laptop or desktop computers, tablet computers, e-book readers, digital cameras, A wide range of devices, including digital recording devices, digital media players, video gaming devices, video game consoles, cellular or satellite radio telephones, so-called "smart phones", video telecommunication devices, video streaming devices, and the like can be incorporated into Digital video devices include 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 Implements video coding techniques, such as those described in the standards defined by Video Coding (HEVC), and extensions of those standards. Video devices may transmit, receive, encode, decode, and/or store digital video information more efficiently by implementing such video coding techniques.

Video coding techniques include spatial (intra-picture) prediction and/or temporal (inter-picture) prediction to reduce or remove redundancy inherent in video sequences. For block-based video coding, a video slice (eg, a video picture or part of a video picture) may be partitioned into video blocks, which may also be divided into 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 with respect to reference samples in neighboring blocks of the same picture. Video blocks in an inter-coded (P or B) slice of a picture may use spatial prediction with respect to reference samples in neighboring blocks of the same picture, or temporal prediction with respect to reference samples in other reference pictures. may be Pictures may be referred to as frames, and reference pictures may be referred to as reference frames.

In general, this disclosure describes techniques for determining a most probable mode (MPM) list for intra prediction and determining an intra prediction mode from the MPM list. The techniques of this disclosure may improve coding efficiency when coding video data using intra prediction. In particular, this disclosure describes techniques for constructing a generic MPM list, and then constructing primary and secondary MPM lists from the generic MPM list. The primary and secondary MPM lists may contain intra prediction modes offset from neighboring blocks as well as intra prediction modes from neighboring blocks. The techniques of this disclosure may improve the efficiency of generating primary and secondary MPM lists.

In one example, a method of decoding video data includes constructing a generic MPM list including N entries (the N entries of the generic MPM list are intra prediction modes, and a plane mode is an ordinal first entry in the generic MPM list). ); constructing a primary MPM list from first Np entries in the general MPM list, where Np is less than N; constructing a secondary MPM list from the remaining (N-Np) entries in the general MPM list; determining a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list; and decoding the current block of video data using the current intra prediction mode to produce a decoded block of video data.

In another example, a device includes a memory and one or more processors, the one or more processors construct a generic MPM list containing N entries (the N entries of the generic MPM list are intra prediction modes, and the planar mode is the generic MPM is the ordinal first entry in the list), constructs a primary MPM list from the first Np entries in the general MPM list (Np is less than N), and constructs a secondary MPM from the remaining (N-Np) entries in the general MPM list. construct a list, determine a current intra prediction mode for a current block of video data using either the primary MPM list or the secondary MPM list, and use the current intra prediction mode to generate a decoded block of video data. It is configured to decode a current block of video data.

In another example, a device includes means for constructing a generic MPM list comprising N entries, wherein the N entries of the generic MPM list are intra prediction modes, and a plane mode is an ordinal first entry in the generic MPM list; means for constructing a primary MPM list from first Np entries in the generic MPM list, where Np is less than N; means for constructing a secondary MPM list from remaining (N-Np) entries in the general MPM list; means for determining a current intra prediction mode for a current block of video data using either the primary MPM list or the secondary MPM list; and means for decoding the current block of video data using the current intra prediction mode to produce a decoded block of video data.

In another example, a non-transitory computer-readable storage medium is encoded with instructions that, when executed, cause a programmable processor to construct a general MPM list comprising N entries comprising: N entries are intra prediction modes, and constitute the general MPM list, wherein a plane mode is an ordinal first entry in the general MPM list; construct a primary MPM list from first Np entries in the general MPM list, wherein Np is less than N; construct a secondary MPM list from the remaining (N-Np) entries in the general MPM list; determine a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list; Decode a current block of video data using the current intra prediction mode to generate a decoded block of video data.

In another example, a device includes a memory and one or more processors, the one or more processors construct a generic MPM list containing N entries (the N entries of the generic MPM list are intra prediction modes, and the planar mode is the generic MPM is the ordinal first entry in the list), constructs a primary MPM list from the first Np entries in the general MPM list (Np is less than N), and constructs a secondary MPM from the remaining (N-Np) entries in the general MPM list. construct a list, determine a current intra prediction mode for a current block of video data using either the primary MPM list or the secondary MPM list, and use the current intra prediction mode to generate an encoded block of video data. It is configured to encode a current block of video data.

The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects and advantages will become apparent from the description, drawings, and claims.

1 is a block diagram illustrating an example video encoding and decoding system that may perform the techniques of this disclosure.
2 is a conceptual diagram illustrating an example of neighboring blocks used to derive an MPM list.
3 is a conceptual diagram illustrating another example of neighboring blocks used to derive an MPM list.
42A and 4B are conceptual diagrams illustrating an exemplary QuadTree Binary Tree (QTBT) structure, and a corresponding Coding Tree Unit (CTU).
5 is a block diagram illustrating an example video encoder that may perform the techniques of this disclosure.
6 is a block diagram illustrating an example video decoder that may perform the techniques of this disclosure.
7 is a flowchart illustrating an example method for encoding a current block according to the techniques of this disclosure.
8 is a flowchart illustrating an example method for decoding a current block according to the techniques of this disclosure.
9 is a flowchart illustrating another example method for encoding a current block according to the techniques of this disclosure.
10 is a flowchart illustrating another example method for decoding a current block according to the techniques of this disclosure.

Versatile Video Coding (VVC) was developed by the Joint Video Experts Team (JVET) of the ITU-T and ISO/IEC to achieve substantial compression capabilities beyond HEVC for a wide range of applications. The VVC specification was finalized in July 2020 and was published by both the ITU-T and ISO/IEC. The VVC specification specifies canonical bitstream and picture formats, high level syntax (HLS) and coding unit level syntax, and parsing and decoding processes. VVC also specifies Profiles/Tiers/Levels (PTL) restrictions, byte stream format, hypothetical reference decoder, and supplemental enhancement information (SEI) in an appendix.

In general, this disclosure describes techniques for determining an MPM list for intra prediction and determining an intra prediction mode from the MPM list. The techniques of this disclosure may improve the efficiency of generating primary and secondary MPM lists. For example, a video encoder and/or a video decoder constructs a generic MPM list containing N entries (the N entries of the generic MPM list are intra prediction modes), and selects 1 from the first Np entries in the generic MPM list. Construct a primary MPM list (Np is less than N), construct a secondary MPM list from the remaining (N-Np) entries in the general MPM list, and use either the primary MPM list or the secondary MPM list to transmit video data. It may also be configured to determine an intra prediction mode for the current block.

1 is a block diagram illustrating an example video encoding and decoding system 100 that may perform the techniques of this disclosure. The techniques of this disclosure generally relate to coding (encoding and/or decoding) video data. Generally, video data includes any data for processing video. Accordingly, video data may include raw, unencoded video, encoded video, decoded (eg, reconstructed) video, and video metadata, such as signaling data.

As shown in FIG. 1 , system 100 includes a source device 102 that provides encoded video data to be decoded and displayed by a destination device 116 in this example. In particular, source device 102 provides video data to destination device 116 via computer readable medium 110 . Source device 102 and destination device 116 can be desktop computers, notebook (i.e., laptop) computers, mobile devices, tablet computers, set-top boxes, telephone handsets such as smartphones, televisions, may include any of a wide variety of devices, including cameras, display devices, digital media players, video gaming consoles, video streaming devices, broadcast receiver devices, and the like. In some cases, source device 102 and destination device 116 may be equipped for wireless communication and may therefore be referred to as wireless communication devices.

In the example of FIG. 1 , source device 102 includes a video source 104 , a memory 106 , a video encoder 200 , and an output interface 108 . Destination device 116 includes input interface 122 , video decoder 300 , memory 120 , and display device 118 . According to this disclosure, video encoder 200 of source device 102 and video decoder 300 of destination device 116 may be configured to apply techniques for deriving an MPM list for intra prediction. Thus, source device 102 represents an example of a video encoding device, while destination device 116 represents an example of a video decoding device. In other examples, a source device and a destination device may include other components or arrangements. For example, source device 102 may receive video data from an external video source, such as an external camera. Likewise, destination device 116 may interface with an external display device, rather than including an integrated display device.

System 100 as shown in FIG. 1 is just one example. In general, any digital video encoding and/or decoding device may perform techniques for deriving an MPM list for intra prediction. Source device 102 and destination device 116 are merely examples of such coding devices from which source device 102 generates coded video data for transmission to destination device 116 . This disclosure refers to a “coding” device as a device that performs coding (encoding and/or decoding) of data. Accordingly, video encoder 200 and video decoder 300 represent examples of coding devices, particularly a video encoder and video decoder, respectively. In some examples, source device 102 and destination device 116 may operate in a substantially symmetric manner such that each of source device 102 and destination device 116 includes video encoding and decoding components. As such, system 100 may support one-way or two-way video transmission between source device 102 and destination device 116, e.g., for video streaming, video playback, video broadcasting, or video telephony. .

In general, video source 104 represents a source of video data (ie, raw, unencoded video data) and directs a sequential series of pictures of the video data to video encoder 200, which encodes the data for the pictures. (also referred to as “frames”). Video source 104 of source device 102 may be a video capture device, such as a video camera, a video archive containing previously captured raw video, and/or video may also include a video feed interface for receiving video from a content provider Alternatively, video source 104 may include computer graphics-based data as source video, or of live video, archived video, and computer-generated video. In each case, video encoder 200 encodes captured, pre-captured, or computer-generated video data. Video encoder 200 encodes pictures in the order they are received (sometimes referred to as " (referred to as “display order”) to a coding order for coding. Video encoder 200 may generate a bitstream that includes the encoded video data. Source device 102 then For example, it may output encoded video data via output interface 108 onto computer readable medium 110 for reception and/or retrieval by input interface 122 of destination device 116 .

Memory 106 of source device 102 and memory 120 of destination device 116 represent general purpose memories. In some examples, memories 106 and 120 may store raw video data, eg, raw video from video source 104 and raw, decoded video data from video decoder 300 . Additionally or alternatively, memories 106 and 120 may store software instructions executable by, eg, video encoder 200 and video decoder 300 , respectively. Memory 106 and memory 120 are shown separately from video encoder 200 and video decoder 300 in this example, but video encoder 200 and video decoder 300 also serve functionally similar or equivalent purposes. It should be understood that it may include internal memories for Moreover, memories 106 and 120 may store encoded video data, eg, output from video encoder 200 and input to video decoder 300 . In some examples, portions of memories 106 and 120 may be allocated as one or more video buffers, eg, to store raw, decoded, and/or encoded video data.

Computer readable medium 110 may represent any type of medium or device capable of transferring encoded video data from source device 102 to destination device 116 . In one example, computer readable medium 110 enables source device 102 to transmit encoded video data directly to destination device 116 in real time, e.g., over a radio frequency network or computer-based network. Indicates a communication medium for enabling In accordance with a communication standard, such as a wireless communication protocol, output interface 108 may modulate a transmission signal containing encoded video data, and input interface 122 may demodulate a received transmission signal. Communication medium may include any wireless or wired communication medium, such as the radio frequency (RF) spectrum or one or more physical transmission lines. The communication medium may form part 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 routers, switches, base stations, or any other equipment that may be useful to facilitate communication from source device 102 to destination device 116 .

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

In some examples, source device 102 may output the encoded video data to a file server 114 or other intermediate storage device that may store the encoded video data generated by source device 102. Destination device 116 may access stored video data from file server 114 via streaming or download.

File server 114 may be any type of server device capable of storing encoded video data and transmitting the encoded video data to destination device 116 . File server 114 may be a web server (e.g., for a website), a server configured to provide file transfer protocol services (such as File Transfer Protocol (FTP) or File Delivery over Unidirectional Transport (FLUTE) protocol), and a content delivery network. (CDN) device, Hypertext Transfer Protocol (HTTP) server, Multimedia Broadcast Multicast Service (MBMS) or Enhanced MBMS (eMBMS) server, and/or Network Attached Storage (NAS) device. 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. .

Destination device 116 may access the encoded video data from file server 114 over any standard data connection, including an Internet connection. This is suitable for accessing encoded video data stored on the file server 114, over a wireless channel (eg, a Wi-Fi connection), over a wired connection (eg, a digital subscriber line (DSL), cable modem, etc.), or a combination of both. 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. there is.

Output interface 108 and input interface 122 are wireless transmitters/receivers, modems, wired networking components (eg, Ethernet cards), wireless communications that operate according to any of the various IEEE 802.11 standards. components, or other physical components. In examples in which output interface 108 and input interface 122 include wireless components, output interface 108 and input interface 122 may be used for 4G, 4G-Long-Term Evolution (LTE), LTE Advanced, 5G, and the like. In accordance with cellular communication standards, it may be configured to transmit data such as encoded video data. In some examples where output interface 108 includes a wireless transmitter, output interface 108 and input interface 122 conform to other wireless standards such as the IEEE 802.11 specification, the IEEE 802.15 specification (eg, ZigBee™), the Bluetooth™ standard, and the like. According to, it may be configured to transmit data such as encoded video data. In some examples, source device 102 and/or destination device 116 may include separate system-on-a-chip (SoC) devices. For example, source device 102 may include video encoder 200 and/or an SoC device to perform functions due to output interface 108 , and destination device 116 may include video decoder 300 and/or a SoC device to perform functions attributed to input interface 122 .

The techniques of this disclosure include over-the-air television broadcast, cable television transmission, satellite television transmission, Internet streaming video transmission, such as dynamic adaptive streaming over HTTP (DASH), encoding onto a data storage medium. may be applied to video coding supporting any of a variety of multimedia applications, such as digital video, decoding of digital video stored on a data storage medium, or other applications.

Input interface 122 of destination device 116 receives the encoded video bitstream from computer readable medium 110 (e.g., communication medium, storage device 112, file server 114, etc.). An encoded video bitstream consists of syntax elements with values describing processing and/or characteristics of video blocks or other coded units (eg, slices, pictures, groups of pictures, sequences, etc.) It may contain signaling information defined by video encoder 200, which is also used by video decoder 300, such as. Display device 118 displays decoded pictures of the decoded video data to a user. 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.

Although not shown in FIG. 1 , in some examples, video encoder 200 and video decoder 300 may be integrated with an audio encoder and/or an audio decoder, respectively, including both audio and video in a common data stream. It may include suitable MUX-DEMUX units, or other hardware and/or software, to handle multiplexed streams. Where applicable, MUX-DEMUX units may conform to the ITU H.223 multiplexer protocol, or other protocols, such as the User Datagram Protocol (UDP).

Video encoder 200 and video decoder 300 each include various suitable encoder and/or decoder circuitry, such as one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programming It may be implemented as any of capable gate arrays (FPGAs), discrete logic, software, hardware, firmware or any combinations thereof. When the techniques are implemented partly in software, a device may store instructions for the software on a suitable, non-transitory computer-readable medium and execute the instructions in hardware using one or more processors to perform the techniques of this disclosure. there is. Each of video encoder 200 and video decoder 300 may be included in one or more encoders or decoders, either of which may be integrated as part of a combined encoder/decoder (CODEC) in a separate device. . A device that includes video encoder 200 and/or video decoder 300 may include an integrated circuit, a microprocessor, and/or a wireless communication device, such as a cellular telephone.

Video encoder 200 and video decoder 300 implement a video coding standard, such as ITU-T H.265, also referred to as High Efficiency Video Coding (HEVC), or extensions thereof, such as multiview and/or scalable It may operate according to video coding extensions. Alternatively, video encoder 200 and video decoder 300 may operate according to other proprietary or industry standards, such as ITU-T H.266, also referred to as Versatile Video Coding (VVC). A draft of the VVC standard is from Bross et al., “Versatile Video Coding (Draft 10),” Joint Video Experts Team (JVET) of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29/WG 11, 18th Meeting: by teleconference, 22 June ? 1 July 2020, JVET-S2001-vA (hereinafter referred to as “VVC Draft 10”). However, the techniques of this disclosure are not limited to any particular coding standard.

In general, video encoder 200 and video decoder 300 may perform block-based coding of pictures. The term “block” generally refers to a structure containing data to be processed (eg, to be encoded, decoded, or otherwise used in an encoding and/or decoding process). For example, a block may include a two-dimensional matrix of samples of luminance and/or chrominance data. In general, video encoder 200 and video decoder 300 may code video data represented in YUV (eg, Y, Cb, Cr) format. That is, rather than coding red, green, and blue (RGB) data for samples of a picture, video encoder 200 and video decoder 300 may code luminance and chrominance components, where chroma The nonce components may include both red hue and blue hue chrominance components. In some examples, video encoder 200 converts received RGB formatted data to a YUV representation prior to encoding, and video decoder 300 converts the YUV representation to RGB format. Alternatively, pre- and post-processing units (not shown) may perform these transformations.

This disclosure may refer generally to coding (eg, encoding and decoding) of pictures to include the process of encoding or decoding data of a picture. Similarly, this disclosure may refer to coding of blocks of a picture to include the process of encoding or decoding data for the blocks, eg, prediction and/or residual coding. An encoded video bitstream typically includes a series of values for syntax elements that indicate coding decisions (eg, coding modes) and partitioning of pictures into blocks. Accordingly, references to coding a picture or block should be generally understood as coding values for syntax elements forming the picture or block.

HEVC defines various blocks that include a coding unit (CU), a prediction unit (PU), and a transform unit (TU). According to HEVC, a video coder (such as video encoder 200) partitions a coding tree unit (CTU) into CUs according to a quadtree structure. That is, the video coder partitions the CTUs and CUs into 4 equal, non-overlapping squares, and each node in the quadtree has 0 or 4 child nodes. Nodes without child nodes may be referred to as “leaf nodes”, and the CUs of these leaf nodes may contain one or more PUs and/or one or more TUs. A video coder may further partition PUs and TUs. For example, in HEVC, Residual Quadtree (RQT) represents the partitioning of TUs.In HEVC, PUs represent inter-prediction data, while TUs represent residual data. Intra-predicted CUs represent intra mode Contains intra prediction information such as indications.

As another example, video encoder 200 and video decoder 300 may be configured to operate according to VVC. According to VVC, a video coder (eg, video encoder 200) partitions a picture into a plurality of coding tree units (CTUs). Video encoder 200 may partition a CTU according to a tree structure, such as a QuadTree Binary Tree (QTBT) structure or a Multi-Type Tree (MTT) structure. The QTBT structure removes the concept of multiple partition types, such as the separation between CUs, PUs, and TUs in HEVC. The QTBT structure includes two levels: a first level partitioned according to quadtree partitioning, and a second level partitioned according to binary tree partitioning. A root node of the QTBT structure corresponds to a CTU. Leaf nodes of binary trees correspond to coding units (CUs).

In the MTT partitioning structure, blocks may be partitioned using quadtree (QT) partitions, binary tree (BT) partitions, and one or more types of triple tree (TT) (also referred to as ternary tree (TT)) partitions. A triple or ternary tree partition is a partition in which a block is split into three sub-blocks. In some examples, a triple or ternary tree partition splits a block into three sub-blocks without splitting the original block through the center. Partitioning types in MTT (eg, QT, BT and TT) may be symmetric or asymmetric.

In some examples, video encoder 200 and video decoder 300 may use a single QTBT or MTT structure to represent each of the luminance and chrominance components, while in other examples, video encoder 200 and video The decoder 300 uses a QTBT/MTT structure for luminance components and another QTBT/MTT structure for both chrominance components (or two QTBT/MTT structures for individual chrominance components). , two or more QTBT or MTT structures may be used.

Video encoder 200 and video decoder 300 may be configured to use quadtree partitioning per HEVC, QTBT partitioning, MTT partitioning, or other partitioning structures. For purposes of explanation, the description of the techniques of this disclosure is presented in terms of QTBT partitioning. However, it should be understood that the techniques of this disclosure may also be applied to video coders configured to use quadtree partitioning, or other types of partitioning as well.

In some examples, a CTU is a coding tree block (CTB) of luma samples, two corresponding CTBs of chroma samples of a picture with three sample arrays, or three separate color planes and syntax used to code the samples. Contains the CTB of samples of a picture or a monochrome picture coded using structures. A CTB may be an NxN block of samples for some value of N such that the division of a component into CTBs is partitioning. A component is an array or a single sample of an array comprising a picture in monochrome format or two arrays (luma and two chroma) comprising a picture in 4:2:0, 4:2:2 or 4:4:4 color format. array from either a single sample. In some examples, a coding block is an NxN block of samples for some values of M and N such that the division of a CTB into coding blocks is partitioning.

Blocks (eg, CTUs or CUs) may be grouped in a variety of ways in a picture. As an example, a brick may refer to a rectangular area of CTU rows within a particular tile in a picture. A tile may be a rectangular area of CTUs within a particular tile column and a particular tile row in a picture. A tile column refers to a rectangular region of CTUs with a height equal to the height of the picture and a width specified by syntax elements (eg, as in a picture parameter set). A tile row refers to a rectangular region of CTUs with a height specified by syntax elements (eg, as in a picture parameter set) and a width equal to the width of the picture.

In some examples, a tile may be partitioned into multiple bricks, each of which may include one or more CTU rows within the tile. A tile that is not partitioned into multiple bricks may also be referred to as a brick. However, bricks that are a true subset of tiles may not be referred to as tiles.

Bricks in a picture may also be arranged into slices. A slice may be an integer number of bricks of a picture that may be included exclusively in a single network abstraction layer (NAL) unit. In some examples, a slice contains only a contiguous sequence of multiple complete tiles or complete bricks of one tile.

This disclosure may use “NxN” and “N by N” interchangeably to refer to the sample dimensions of a block (such as a CU or other video block) in terms of vertical and horizontal dimensions, e.g., 16x16 samples or 16 by 16 samples. In general, a 16x16 CU will have 16 samples in the vertical direction (y = 16) and 16 samples in the horizontal direction (x = 16). Similarly, an NxN CU typically has N samples in the vertical direction and N samples in the horizontal direction, where N denotes a non-negative integer value. Samples in a CU may be arranged in rows and columns. Moreover, CUs do not necessarily have the same number of samples in the horizontal direction as in the vertical direction. For example, CUs may contain N×M samples, where M is not necessarily equal to N.

Video encoder 200 encodes video data for CUs representing prediction and/or residual information, and other information. Prediction information indicates how a CU is to be predicted in order to form a predictive block for the CU. Residual information generally indicates sample-by-sample differences between samples of a CU before encoding and a prediction block.

To predict a CU, video encoder 200 may form a predictive block for the CU, generally via inter-prediction or intra-prediction. Inter-prediction generally refers to predicting a CU from data of a previously coded picture, whereas intra-prediction generally refers to predicting a CU from previously coded data of the same picture. To perform inter-prediction, video encoder 200 may use one or more motion vectors to generate a predictive block. Video encoder 200 may generally perform a motion search to identify a reference block that closely matches a CU, eg, in terms of differences between the CU and the reference block. Video encoder 200 uses a sum of absolute difference (SAD), sum of squared differences (SSD), average absolute difference to determine whether a reference block closely matches the current CU. A difference metric may be calculated using mean absolute difference (MAD), mean squared differences (MSD), or other such difference calculations. In some examples, video encoder 200 may predict the current CU using uni-prediction or bi-prediction.

Some examples of VVC also provide an affine motion compensation mode, which may be considered an inter prediction mode. In an affine motion compensation mode, video encoder 200 may determine two or more motion vectors representing non-translational motion, such as zooming in or out, rotation, perspective motion, or other irregular motion types.

To perform intra prediction, video encoder 200 may select an intra prediction mode to generate a predictive block. Some examples of VVC provide 67 intra-prediction modes, including planar mode and DC mode, as well as various directional modes. In general, video encoder 200 selects an intra-prediction mode that describes neighboring samples for a current block (eg, a block of a CU) from which to predict samples of the current block. Such samples are generally in the same picture as the current block, above, above the current block, assuming that video encoder 200 codes the CTUs and CUs in raster scan order (left to right, top to bottom). and may be on the left, or on the left.

Video encoder 200 encodes data representing a prediction mode for a current block. For example, for inter-prediction modes, video encoder 200 may encode data indicating which of the various available inter-prediction modes is being used, as well as motion information for the corresponding mode. For uni- or bi-directional inter-prediction, for example, video encoder 200 may encode motion vectors using advanced motion vector prediction (AMVP) or merge mode. Video encoder 200 may encode motion vectors for an affine motion compensation mode using similar modes.

Following prediction, such as intra-prediction or inter-prediction, of a block, video encoder 200 may calculate residual data for the block. Residual data, such as a residual block, represents sample-by-sample differences between a block and the prediction block for the block, formed using the corresponding prediction mode. Video encoder 200 may apply one or more transforms to the residual block to produce transformed data in the transform domain instead of the sample domain. For example, 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. Additionally, video encoder 200 may apply a secondary transform following 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. Video encoder 200 produces transform coefficients following application of one or more transforms.

As mentioned above, following any transforms to generate transform coefficients, video encoder 200 may perform quantization of the transform coefficients. Quantization generally refers to a process in which transform coefficients are quantized to reduce the amount of data used to represent the transform coefficients, thereby providing additional compression. By performing the quantization process, video encoder 200 may reduce the bit depth associated with some or all of the transform coefficients. For example, video encoder 200 may round down an n-bit value to an m-bit value during quantization, where n is greater than m. In some examples, to perform quantization, video encoder 200 may perform a bitwise right-shift of the value to be quantized.

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

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

Video encoder 200 sends syntax data, such as block-based syntax data, picture-based syntax data, and sequence-based syntax data, to video decoder 300, such as picture headers, block headers, slice headers, or other syntax data. , such as a sequence parameter set (SPS), a picture parameter set (PPS), or a video parameter set (VPS). Similarly, video decoder 300 may decode such syntax data to determine how to decode the corresponding video data.

In this way, video encoder 200 converts encoded video data, e.g., syntax elements that describe the partitioning of a picture into blocks (e.g., CUs) and bits that contain prediction and/or residual information for the blocks. You can also create streams. Ultimately, video decoder 300 may receive the bitstream and decode the encoded video data.

In general, video decoder 300 performs a process that is reversible to that performed by video encoder 200 to decode encoded video data of a bitstream. For example, video decoder 300 may decode values for syntax elements of a bitstream using CABAC in a manner substantially similar to, but reciprocal to, the CABAC encoding process of video encoder 200. Syntax elements may define partitioning information for partitioning of a picture into CTUs and partitioning of each CTU according to a corresponding partition structure, such as a QTBT structure, to define the CUs of a CTU. Syntax elements may further define prediction and residual information for blocks of video data (eg, CUs).

Residual information may be represented by quantized transform coefficients, for example. Video decoder 300 may inverse quantize and inverse transform the quantized transform coefficients of the block to reconstruct a residual block for the block. Video decoder 300 uses the signaled prediction mode (intra- or inter-prediction) and related prediction information (eg, motion information for inter-prediction) to form a predictive block for a block. Video decoder 300 may then combine the predictive block and the residual block (on a sample-by-sample basis) to reconstruct the original block. Video decoder 300 may perform additional processing, such as performing a deblocking process to reduce visual artifacts along the boundaries of a block.

This disclosure may generally refer to “signaling” certain information, such as syntax elements. The term “signaling” generally refers to syntax elements used to decode encoded video data and/or other data. It may refer to the communication of values. That is, video encoder 200 may signal values for syntax elements in a bitstream. Generally, signaling refers to generating a value in a bitstream. As mentioned above As noted, source device 102 transmits the destination bitstream in non-real-time or substantially real-time, as may occur when storing syntax elements to storage device 112 for later retrieval by destination device 116. device 116.

According to the techniques of this disclosure, as will be described in more detail below, video encoder 200 and video decoder 300 construct a generic MPM list comprising N entries (where the N entries of the generic MPM list are Intra prediction modes, where the plane mode is the ordinal first entry in the general MPM list), constructs a primary MPM list from the first Np entries in the general MPM list (Np is less than N), and the rest in the general MPM list ( N-Np) entries to construct a secondary MPM list, use the primary MPM list or the secondary MPM list to determine a current intra prediction mode for a current block of video data, and use the current intra prediction mode to It may also be configured to decode a current block of video data.

Exemplary intra-coding modes include a DC mode, a planar mode, and a plurality of directional modes (eg, non-planar modes). VVC, J. Chen, Y. Ye, S.-H. Kim, "Algorithm description for Versatile Video Coding and Test Model 9 (VTM 9)", JVET-R2002, Apr. In 2020, 65 directional modes are used for intra prediction of blocks. To code the intra mode value, video encoder 200 and video decoder 300 may be configured to derive a most probable mode (MPM) list. If the intra mode used to code a particular CU is a mode in the MPM list, video encoder 200 may signal only the index of the determined intra mode in the MPM list. Otherwise, video encoder 200 may signal the mode value using bypass coding (eg, entropy coding with a fixed probability model).

In VVC, there are 6 entries in the MPM list. The first entry in the MPM list is planar mode. The remaining entries of the MPM list are the intra modes of the left (L) and upper (A) neighboring blocks of CU 400 (see FIG. 2 ), the intra modes derived from the directional intra modes of the neighboring blocks, and the default It consists of intra modes. For the remainder of the discussion in this disclosure, this MPM list will be referred to as the primary MPM list.

A. "CE3-3.1.1: Two MPM modes and shape dependency (Test 3.1.1)" by Ramasuramonian, et al., JVET (Joint Video Exploration Team), 11th meeting: Ljubljana, SI, July 10-18, 2018 (hereinafter "JVET-K0081"), two MPM lists were proposed. One MPM list is a primary MPM (PMPM) list with 6 entries, and another MPM list is a secondary MPM (SMPM) list with 16 entries. Entries in the PMPM list are left (L), top (A), bottom-left (BL), top-right (AR), and top-left (AL) of CU 402, as shown in FIG. ) is derived using intra modes of neighboring blocks. The SMPM list is generated from modes that are close (eg, close in angle or index value) to the directional modes included in the PMPM list.

For example, if the first entry of the PMPM list is intra mode 12 and the maximum offset is 4, intra modes 11, 10, 9, 8, 13, 14, 15 and 16 are added to the SMPM list, respectively, provided that: This intra mode is not yet included in the two MPM lists. That is, all modes plus or minus 4 indices from intra mode index 12 are added to the list unless those modes are duplicates of modes already in the list.

The maximum offset used for the 6 primary MPMs in JVET-K0081 is {4, 3, 3, 2, 2, 1}. If 16 entries of the SMPM list are not populated by this process, the remaining entries are populated from the default list of intra modes. A video encoder may signal syntax elements that indicate whether the intra prediction mode for a block is from the PMPM list or the SMPM list.

This disclosure describes different techniques for improving the construction of MPM lists composed of PMPM lists and SMPM lists. In particular, this disclosure describes techniques for constructing a generic MPM list, and then constructing primary and secondary MPM lists from the generic MPM list. The primary and secondary MPM lists may contain intra prediction modes offset from neighboring blocks as well as intra prediction modes from neighboring blocks.

General MPM List Construction

First, a generic MPM (GMPM) list may be defined with N entries, where the i-th entry of the GMPM list is denoted as GMPM[ i ]. The first entry in this GMPM list is planar mode. That is, index 0 into the GMPM list (eg, GMPM[0]) indicates the planar intra mode. For example, as shown in FIG. 3, the left (L), top (A), bottom-left (BL), top-right (AR), and top-left (AL) neighboring blocks of the currently coded block. The intra modes of may be denoted as MPM(L), MPM(A), MPM(BL), MPM(AR), and MPM(AL), respectively.

Video encoder 200 and video decoder 300, if MPM(j) is available and not yet included in the GMPM list, the intra modes MPM(L), MPM(A), MPM(BL), MPM( AR), and MPM(AL) to the GMPM list. Intra-mode MPM(j) is available if neighboring block j has an associated intra-prediction mode. For example, a neighboring block may have an associated intra prediction mode if the neighboring block is coded using intra prediction. In other examples, a neighboring block may have an associated intra prediction mode even though it is not coded using intra prediction.

Video encoder 200 and video decoder 300 select the first Na available directional intra prediction modes from among MPM(L), MPM(A), MPM(BL), MPM(AR), and MPM(AL) intra prediction modes. The remaining entries in the GMPM list may be derived by offsetting the modes, where Na is left (L), top (A), bottom-left (BL), top-right (AR), and top-left (AL) It is a number smaller than the number of neighboring blocks. For example, Na may be less than 5.

The intra modes of MPM(L), MPM(A), MPM(BL), MPM(AR), and MPM(AL) included in the GMPM list are represented by GMPM[p] = MPM(j), where 1 ≤ p ≤ Nb, Nb is 5 or less, and j is one of L, A, BL, AR, and AR. If p is less than the predefined value q, the maximum offset is set to M1; Otherwise, the maximum offset is set to M2. If the N entries of the GMPM list are not populated by the proposed process, the rest of the entries are populated from the default list. The first Np entries in the GMPM list are set as the PMPM list, and the rest of the entries (N - Np) in the GMPM list are set as the SMPM list.

As an example, if the first entry of the PMPM list is intra mode 12 and the maximum offset is 4, intra modes 11, 10, 9, 8, 13, 14, 15 and 16 are added to the SMPM list, respectively, provided that these Intra modes are not yet included in the two MPM lists. That is, all of the modes plus or minus 4 indices from intra mode index 12 are added to the list unless those modes overlap with modes already in the list. In another example, if the first entry of the PMPM list is intra mode 12 and the maximum offset is 3, intra modes 11, 10, 9, 13, 14, and 15 are added to the SMPM list, respectively, provided that this intra mode It is not yet included in the two MPM lists. That is, all modes plus or minus 3 indices from intra mode index 12 are added to the list, unless those modes are duplicates of modes already in the list.

In one example, N = 22, Np = 6, Na = 2, q = 3, M1 = 4, and M2 = 3. In this example, the size of the GMPM list is 22 entries, where the first 6 entries are the PMPM list and the last 16 entries are the SMPM list. The first two available directional intra modes of MPM(L), MPM(A), MPM(BL), MPM(AR) and MPM(AL) are directional intra modes adjacent to the two available directional intra modes. Offset to derive. In this context, neighborhood means plus or minus M1 or M2 indices from the index of available directional intra modes. If GMPM[ 1 ] and GMPM[ 2 ] are non-DC modes, the maximum offset is 4 for GMPM[ 1 ] and GMPM[ 2 ]. If GMPM[ 1 ] is DC mode, and GMPM[ 2 ] and GMPM[ 3 ] are non-DC modes, the maximum offset is 4 for GMPM[ 2 ] and 3 for GMPM[ 3 ]. If GMPM[ 2 ] is DC mode, and GMPM[ 1 ] and GMPM[ 3 ] are non-DC modes, the maximum offset is 4 for GMPM[ 1 ] and 3 for GMPM[ 3 ]. For example, if GMPM[ 1 ] = 20, and GMPM[ 3 ] = 40, then modes 16, 17, 18, 19, 21, 22, 23, and 24 and GMPM[ 3 ] offset from GMPM[ 1 ] Modes 37, 38, 39, 41, 42, and 43 offset from are added to the GMPM list.

MPM index coding

In one example for VVC, video decoder 300 may be configured to first decode and parse the plane flag to determine whether the intra mode for the CU is the first entry in the PMPM list. If the plane flag does not indicate a plane mode, video decoder 300 may be configured to decode and parse an index value (eg, a syntax element indicating an index value) to determine which entry of the PMPM list is selected. . The parsed index values 0, 1, 2, 3, and 4 correspond to the 1st, 2nd, 3rd, 4th, and 5th entries of the PMPM list, respectively, and index values 0, 1, 2, 3, 4 Note that the parsed bins for are 0, 10, 110, 1110, 1111 respectively.

New coding tools named ISP (Intra Sub-Partition) mode and MRL (Multiple reference line) mode have been incorporated into VVC. ISP mode and regular intra mode share the same PMPM list. The MRL mode applies to intra modes in the PMPM list except for the first entry, namely the planner mode. Because regular intra mode, ISP mode, and MRL mode all share the same non-planar PMPM entries, i.e., the 1st, 2nd, 3rd, 4th, 5th entries of the PMPM list, regular intra mode, ISP mode, and context coding conditioned for the selected one of the MRL modes will improve coding efficiency when signaling the PMPM index. Thus, according to the techniques of this disclosure, video encoder 200 and video decoder 300 may be configured to use three context models to code the first bin of non-planar PMPM indices as follows:

If (ISP mode): Code the first bin of non-planar PMPM indices with context index 0.

Otherwise, if (MRL mode): Code the first bin of non-planar PMPM indices with context index 1.

Otherwise (regular intra mode): Code the first bin of non-planar PMPM indices with context index 2.

The order of if-else can be changed in other combinations when using the techniques of this disclosure. An example is:

If (MRL mode): Code the first bin of non-planar PMPM indices with context index 0.

Otherwise, if (ISP mode): Code the first bin of non-planar PMPM indices with context index 1.

Otherwise (regular intra mode): Code the first bin of non-planar PMPM indices with context index 2.

yes

As mentioned above, two MPM lists may be used: one is a primary MPM (PMPM) list with 6 entries, and the other is a secondary MPM (SMPM) list with 16 entries.

According to the techniques of this disclosure, video encoder 200 and video decoder 300 may construct a general MPM list having 22 entries, where the first 6 entries in the general MPM list are included, and the rest of the 22 entries are set to the SMPM list. The first entry (eg, the ordinal first entry) of the general MPM list is the planar mode. The remaining entries are intra modes of left (L), top (A), bottom-left (BL), top-right (AR), and top-left (AL) neighboring blocks, as shown in FIG. directional modes offset from the first two available directional modes of neighboring blocks, and default modes. If a CU block is rectangular and vertically oriented, that is, when its height is greater than its width, the order of neighboring blocks checked for available intra prediction modes is A, L, BL, AR, AL. Otherwise, the order is L, A, BL, AR, AL.

The maximum offset for a directional mode of neighboring blocks depends on the entry point of this directional mode in the general MPM list. If the available directional mode of the neighboring block is in either the 2nd or 3rd entry (note that the 1st entry is a planar mode), the maximum offset is set to 4, otherwise the maximum offset is set to 3. For example, the i-th entry of a general MPM list is denoted by GMPM[ i ]. GMPM[ 0 ] = planar mode. If GMPM[ 1 ] is DC mode, and GMPM[ 2 ] and GMPM[ 3 ] are directional modes, the maximum offset is 4 for GMPM[ 2 ] and 3 for GMPM[ 3 ]. Assume that GMPM[ 2 ] = 20 and GMPM[ 3 ] = 40. Then 16, 17, 18, 19, 21, 22, 23 and 24 offset from GMPM[ 2 ] and 37, 38, 39, 41, 42 and 43 offset from GMPM[ 3 ] are added to the GMPM list.

Video decoder 300 may first decode and parse the plane flag to determine whether the intra mode for the CU is the first entry in the PMPM list. If the planar flag does not indicate that a planar mode is to be used, video decoder 300 decodes and parses the index value for the non-planar mode of the PMPM list to determine which entry of the PMPM list is selected. The parsed index values 0, 1, 2, 3, 4 for the non-planar mode correspond to the 1st, 2nd, 3rd, 4th, 5th entries of the PMPM list, and the index values 0, 1, 2, Note that the parsed bins for 3 and 4 are 0, 10, 110, 1110, and 1111 respectively. Video encoder 200 and video decoder 300 may be configured to use three context models to code the first bin of indices for non-planar modes in the PMPM list as follows:

If (ISP): Code the first bin with context index 0.

Otherwise, if (MRL): Code the first bin with context index 1.

Otherwise (Regular Intra): Code the first bin with context index 2.

In summary, in one example of this disclosure, video decoder 300 may be configured to decode a current block of video data using intra prediction. Video decoder 300 may be configured to build a generic MPM list that includes N entries, where the N entries of the generic MPM list are intra prediction modes and the planar mode is the ordinal first entry in the generic MPM list. . Video decoder 300 may also build a primary MPM list from the first Np entries in the general MPM list, where Np is less than N, and the remaining (N-Np) entries in the general MPM list. A secondary MPM list may be constructed from And, video decoder 300 uses the primary MPM list or the secondary MPM list to determine a current intra prediction mode for a current block of video data, and to use the current intra prediction mode to generate a decoded block of video data. can also be used to decode the current block of video data. In one example, N is 22 and Np is 6.

In one example, to determine the current intra prediction mode, video decoder 300 may be further configured to decode an index into the primary MPM list or the secondary MPM list, where the index is the primary MPM list or Indicates a non-planar intra prediction mode in the secondary MPM list. Video decoder 300 may determine a current intra prediction mode for a current block of video data based on the index.

In a further example, to decode an index into a primary MPM list or a secondary MPM list, video decoder 300 adds context for entropy decoding the first bin of the index based on the coding tool used for the current block. , and the first bin of the index may be entropy-decoded using the context. In one example, the coding tool is one of regular intra prediction mode, intra sub-partition mode, or multiple reference line mode.

In another example of this disclosure, to build a general MPM list, video decoder 300 adds each intra prediction modes from each neighboring block of a current block of video data to the general MPM list, and It may also be configured to add a plurality of intra prediction modes offset from respective intra prediction modes from the blocks to the general MPM list. In one example, video decoder 300 determines each intra-prediction mode from each neighboring blocks of a current block of video data, based on which intra-prediction modes are available and have not yet been added to the general MPM list. may be added to the general MPM list.

In another example, to determine a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list, video decoder 300 uses the current MPM from the primary MPM list or secondary MPM list. It may be configured to decode the syntax element indicating the list, decode the index to the current MPM list, and determine the current intra prediction mode from the index to the current MPM list.

In a reciprocal manner, video encoder 200 is also configured to encode a current block of video data using intra prediction. Video encoder 200 may be configured to build a generic MPM list that includes N entries, where the N entries of the generic MPM list are intra prediction modes and the planar mode is the ordinal first entry in the generic MPM list. . Video encoder 200 may also construct a primary MPM list from the first Np entries in the general MPM list, where Np is less than N, and the remaining (N-Np) entries in the general MPM list. A secondary MPM list may be constructed from Video encoder 200 also determines a current intra-prediction mode for a current block of video data using either the primary MPM list or the secondary MPM list, and uses the current intra-prediction mode to generate an encoded block of video data. can also be used to encode the current block of video data. In one example, N is 22 and Np is 6.

In one example of this disclosure, video encoder 200 may be configured to encode an index into a primary MPM list or a secondary MPM list, where the index is a non-plane in the primary MPM list or secondary MPM list. Indicates intra prediction mode.

In another example of this disclosure, to encode an index into a primary MPM list or a secondary MPM list, video encoder 200 performs entropy encoding of a first bin of the index based on a coding tool used for the current block. It may be configured to determine a context and use the context to entropy encode the first bin of the index. In one example, the coding tool is one of regular intra prediction mode, intra sub-partition mode, or multiple reference line mode.

In another example, to build the general MPM list, video encoder 200 also adds each intra prediction mode from each neighboring block of the current block of video data to the general MPM list, and each neighboring block and add a plurality of intra prediction modes offset from respective intra prediction modes from the general MPM list. Video encoder 200 assigns each intra-prediction mode from each neighboring block of a current block of video data to a generic MPM list, based on which respective intra-prediction modes are available and have not yet been added to the generic MPM list. can also be added to

4A and 4B are conceptual diagrams illustrating an example quadtree binary tree (QTBT) structure 130 , and corresponding coding tree unit (CTU) 132 . Solid lines represent quadtree splitting, and dotted lines represent binary tree splitting. At each splitted (i.e. non-leaf) node of the binary tree, one flag is signaled to indicate which splitting type (i.e. horizontal or vertical) is being used, in this example 0 is Indicates horizontal splitting and 1 indicates vertical splitting. For quadtree splitting, there is no need to indicate the splitting type because quadtree nodes horizontally and vertically split a block into four subblocks with the same size. Accordingly, the syntax elements for the domain tree level (i.e., solid lines) of the QTBT structure 130 (e.g., segmentation information) and the syntax elements for the prediction tree level (i.e., dotted lines) of the QTBT structure 130 (i.e., dotted lines) video encoder 200 may encode, and video decoder 300 may decode. Video encoder 200 may encode, and video decoder 300 may decode video data, such as prediction and transform data, for the CUs represented by the terminal leaf nodes of QTBT structure 130. .

In general, CTU 132 of FIG. 4B may be associated with parameters defining the sizes of blocks corresponding to nodes of QTBT structure 130 at first and second levels. These parameters are CTU size (representing the size of CTU 132 in samples), minimum quadtree size (MinQTSize, representing minimum allowed quadtree leaf node size), maximum binary tree size (MaxBTSize, maximum allowed binary tree size). root node size), maximum binary tree depth (MaxBTDepth, indicating maximum allowed binary tree depth), and minimum binary tree size (MinBTSize, indicating minimum allowed binary tree leaf node size).

A root node of the QTBT structure corresponding to a CTU may have four child nodes at the first level of the QTBT structure, each of which may be partitioned according to quadtree partitioning. That is, nodes at the first level are either leaf nodes (no child nodes) or have 4 child nodes. The example of QTBT structure 130 shows such nodes as including child nodes and a parent node with solid lines for branches. If the nodes of the first level are not larger than the maximum allowed binary tree root node size (MaxBTSize), the nodes may be further partitioned by individual binary trees. Binary tree splitting of one node may be repeated until nodes resulting from splitting reach the minimum allowed binary tree leaf node size (MinBTSize) or the maximum allowed binary tree depth (MaxBTDepth). The example of QTBT structure 130 shows such nodes as having dotted lines for branches. A binary tree leaf node is referred to as a coding unit (CU) used for prediction (eg, intra-picture or inter-picture prediction) and transformation, without any further partitioning. As discussed above, CUs may also be referred to as “video blocks” or “blocks”.

In one example of the QTBT partitioning structure, the CTU size is set as 128x128 (luma samples and two corresponding 64x64 chroma samples), MinQTSize is set as 16x16, MaxBTSize is set as 64x64, (both width and height ) MinBTSize is set as 4, and MaxBTDepth is set as 4. Quadtree partitioning is first applied to the CTU to create quad-tree leaf nodes. Quadtree leaf nodes may have a size from 16x16 (ie, MinQTSize) to 128x128 (ie, CTU size). If the quadtree leaf node is 128x128, then the leaf quadtree node will not be further split by the binary tree because the size exceeds MaxBTSize (ie 64x64 in this example). Otherwise, the quadtree leaf nodes will be further partitioned by the binary tree. Thus, a quadtree leaf node is also the root node for a binary tree, and has a binary tree depth of zero. When the binary tree depth reaches MaxBTDepth (4 in this example), no further splitting is allowed. A binary tree node with a width equal to MinBTSize (in this example, 4) implies that no further vertical splitting (ie splitting of width) is allowed for that binary tree node. Similarly, a binary tree node with a height equal to MinBTSize implies that no further horizontal splits (ie, splits of height) are allowed for that binary tree node. As mentioned above, the leaf nodes of the binary tree are referred to as CUs and are further processed according to prediction and transformation without further partitioning.

5 is a block diagram illustrating an example video encoder 200 that may perform the techniques of this disclosure. 5 is provided for purposes of explanation and should not be considered limiting of the techniques as generally exemplified and described in this disclosure. For purposes of explanation, this disclosure describes a video decoder 200 in accordance with the 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 video encoding devices configured for other video coding standards.

In the example of FIG. 5 , video encoder 200 includes video data memory 230 , mode select unit 202 , residual generation unit 204 , transform processing unit 206 , quantization unit 208 , inverse quantization unit ( 210 ), inverse transform processing unit 212 , reconstruction unit 214 , filter unit 216 , decoded picture buffer (DPB) 218 , and entropy encoding unit 220 . Video data memory 230, mode selection unit 202, residual generation unit 204, transform processing unit 206, quantization unit 208, inverse quantization unit 210, inverse transform processing unit 212, reconstruction Any or all of unit 214 , filter unit 216 , DPB 218 , and entropy encoding unit 220 may be implemented in one or more processors or in processing circuitry. For example, the units of video encoder 200 may be implemented as one or more circuits or logic elements as part of hardware circuitry, or as part of a processor, ASIC, or FPGA. Moreover, video encoder 200 may include additional or alternative processors or processing circuitry to perform these and other functions.

Video data memory 230 may store video data to be encoded by the components of video encoder 200 . Video encoder 200 may receive video data stored in video data memory 230 , eg, from video source 104 ( FIG. 1 ). DPB 218 may act as a reference picture memory that stores reference video data for use in prediction of subsequent video data by video encoder 200 . Video data memory 230 and DPB 218 may be memory devices such as dynamic random access memory (DRAM) including synchronous DRAM (SDRAM), magnetoresistive RAM (MRAM), resistive RAM (RRAM), or other types of memory devices. It may be formed by any of the memory devices. Video data memory 230 and DPB 218 may be provided by the same memory device or separate memory devices. In various examples, video data memory 230 may be on-chip with or off-chip with other components of video encoder 200 as illustrated.

In this disclosure, reference to video data memory 230 is limited to memory internal to video encoder 200 unless specifically described as such, or memory external to video encoder 200 unless specifically described as such. should not be construed as Rather, reference to video data memory 230 should be understood as a reference memory that stores video data that video encoder 200 receives for encoding (eg, video data for a current block to be encoded). Memory 106 of FIG. 1 may also provide temporary storage of outputs from various units of video encoder 200 .

The various units of FIG. 5 are illustrated to aid understanding of the operations performed by video encoder 200 . Units may be implemented as fixed function circuits, programmable circuits, or a combination of both. Fixed function circuits refer to circuits that provide specific functions and are preset for operations that can be performed. Programmable circuits refer to circuits that can be programmed to perform various tasks and provide flexible functionality in the operations that can be performed. For example, programmable circuits may execute software or firmware that causes the programmable circuits to operate in a manner defined by instructions in the software or firmware. Fixed function circuits may execute software instructions (eg, to receive parameters or output parameters), but the types of operations they perform are generally immutable. In some examples, one or more of the units may be discrete circuit blocks (fixed function or programmable), and in some examples, one or more of the units may be integrated circuits.

Video encoder 200 may include arithmetic logic units (ALUs), elementary function units (EFUs), digital circuits, analog circuits, and/or programmable cores formed from programmable circuits. may be In examples where the operations of video encoder 200 are performed using programmable circuits, software executed by memory 106, memory 106 (FIG. 1) includes software that video encoder 200 receives and executes. of instructions (eg, object code), or other memory within video encoder 200 (not shown) may store such instructions.

Video data memory 230 is configured to store received video data. Video encoder 200 may retrieve a picture of video data from video data memory 230 and provide the video data to residual generation unit 204 and mode select unit 202 . Video data in video data memory 230 may be raw video data to be encoded.

Mode select unit 202 includes motion estimation unit 222 , motion compensation unit 224 , and intra-prediction unit 226 . Mode select unit 202 may include additional functional units to perform video prediction according to other prediction modes. As examples, mode select unit 202 may be a palette unit, an intra-block copy unit (which may be part of motion estimation unit 222 and/or motion compensation unit 224), an affine unit, a linear model (LM) unit etc. may be included.

Mode select unit 202 typically coordinates multiple encoding passes to test combinations of encoding parameters and resulting rate-distortion values for those combinations. Encoding parameters may include partitioning of CTUs into CUs, prediction modes for CUs, transform types for residual data of CUs, quantization parameters for residual data of CUs, and the like. Mode select unit 202 may ultimately select a combination of encoding parameters with better rate-distortion values than other tested combinations.

Video encoder 200 may partition a picture retrieved from video data memory 230 into a series of CTUs and encapsulate one or more CTUs within a slice. Mode select unit 202 may partition the CTUs of a picture according to a tree structure, such as the quadtree structure or QTBT structure of HEVC described above. As described above, video encoder 200 may form one or more CUs from partitioning a CTU according to a tree structure. Such a CU may also be referred to generically as a “video block” or “block”.

In general, mode select unit 202 also controls components thereof (e.g., motion estimation unit 222, motion compensation unit 224, and intra-prediction unit 226) to obtain a current block (e.g., current CU , or, in HEVC, overlapping parts of PUs and TUs). For inter-prediction of a current block, motion estimation unit 222 uses one or more reference pictures (one or more previously coded pictures stored in DPB 218) to identify one or more closely matching reference blocks. Motion search can also be performed. In particular, motion estimation unit 222 calculates a potential reference block, e.g., according to a sum of absolute differences (SAD), a sum of squared differences (SSD), a mean absolute difference (MAD), mean squared differences (MSD), and the like. You can also calculate a value indicating how similar it is to the current block. Motion estimation unit 222 may perform these calculations using the sample-by-sample differences between the reference block and the current block generally considered. Motion estimation unit 222 may identify the reference block with the lowest value resulting from these calculations that indicates the reference block that most closely matches the current block.

Motion estimation unit 222 may form one or more motion vectors (MVs) that define positions of reference blocks in reference pictures relative to the position of the current block in the current picture. Motion estimation unit 222 may then provide the motion vectors to motion compensation unit 224 . For example, for unidirectional inter-prediction, motion estimation unit 222 may provide a single motion vector, whereas for bidirectional inter-prediction, motion estimation unit 222 may provide two motion vectors. may be Motion compensation unit 224 may then use the motion vectors to generate a predictive block. For example, motion compensation unit 224 may use the motion vector to retrieve the data of the reference block. As another example, if the motion vector has fractional-sample precision, motion compensation unit 224 may interpolate values for the predictive block according to one or more interpolation filters. Moreover, for bi-directional inter-prediction, motion compensation unit 224 retrieves data for two reference blocks identified by separate motion vectors, e.g., via sample-by-sample averaging or weighted averaging. Data can also be combined.

As another example, for intra-prediction, or intra-predictive coding, intra-prediction unit 226 may generate a predictive block from samples neighboring the current block. For example, for directional modes, intra-prediction unit 226 generally mathematically combines the values of neighboring samples, and populates these computed values in a direction defined over the current block to populate the prediction block can also create As another example, for the DC mode, intra-prediction unit 226 may calculate an average of neighboring samples for the current block and generate a predictive block to include this resulting average for each sample of the predictive block. there is.

According to the techniques of this disclosure described above, intra-prediction unit 226 constructs a general MPM list containing N entries (the N entries of the general MPM list are intra prediction modes, and the planar mode is the general MPM list is the ordinal first entry in the general MPM list), constructs a primary MPM list from the first Np entries in the general MPM list (Np is less than N), and constructs a secondary MPM list from the remaining (N-Np) entries in the general MPM list , determine a current intra-prediction mode for a current block of video data using either the primary MPM list or the secondary MPM list, and use the current intra-prediction mode to generate an encoded block of video data. It may also be configured to encode the current block of data.

Mode select unit 202 provides the predictive block to residual generation unit 204. Residual generation unit 204 receives a raw, unencoded version of the current block from video data memory 230 and a predictive block from mode select unit 202 . Residual generation unit 204 calculates sample-by-sample differences between the current block and the predictive block. The sample-by-sample differences of the result define the residual block relative to the current block. In some examples, residual generation unit 204 may also determine differences between sample values in a residual block to generate the residual block using residual differential pulse code modulation (RDPCM). In some examples, residual generation unit 204 may be formed using one or more subtractor circuits that perform binary subtraction.

In examples in which mode select unit 202 partitions CUs into PUs, each PU may be associated with a luma prediction unit and corresponding chroma prediction units. Video encoder 200 and video decoder 300 may support PUs having various sizes. As indicated above, the size of a CU may refer to the size of the CU's luma coding block and the size of a PU may refer to the size of the PU's luma prediction unit. Assuming that the size of a particular CU is 2Nx2N, video encoder 200 supports PU sizes of 2Nx2N or NxN for intra-prediction, and symmetric PUs of 2Nx2N, 2NxN, Nx2N, NxN, or the like for inter-prediction. sizes may be supported. Video encoder 200 and video decoder 300 may also support asymmetric partitioning on PU sizes of 2NxnU, 2NxnD, nLx2N, and nRx2N for inter prediction.

In examples in which mode select unit 202 does not further partition a CU into PUs, each CU may be associated with a luma coding block and corresponding chroma coding blocks. As above, the size of a CU may refer to the size of a luma coding block of the CU. Video encoder 200 and video decoder 300 may support CU sizes of 2Nx2N, 2NxN, or Nx2N.

As some examples, for other video coding techniques, such as intra-block copy mode coding, affine mode coding, and linear model (LM) mode coding, mode select unit 202 may use separate units associated with the coding techniques. , generates a prediction block for the current block to be encoded. In some examples, such as palette mode coding, mode select unit 202 may not generate a predictive block, but instead may generate syntax elements indicating how to reconstruct the block based on the selected palette. In these modes, mode select unit 202 may provide these syntax elements to entropy encoding unit 220 to be encoded.

As described above, residual generation unit 204 receives video data for a current block and a corresponding predictive block. Residual generation unit 204 then generates a residual block for the current block. To generate a residual block, residual generation unit 204 calculates sample-by-sample differences between the current block and the predictive block.

Transform processing unit 206 applies one or more transforms to the residual block to produce a block of transform coefficients (referred to herein as a “transform coefficient block”). Transform processing unit 206 may apply various transforms to the residual block to form a transform coefficient block. For example, 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, transform processing unit 206 may perform multiple transforms on the residual block, eg, a primary transform and a secondary transform, such as a rotation transform. In some examples, transform processing unit 206 does not apply transforms to the residual block.

Quantization unit 208 may quantize the transform coefficients in the transform coefficient block to produce a quantized transform coefficient block. Quantization unit 208 may quantize the transform coefficients of a transform coefficient block according to a quantization parameter (QP) value associated with the current block. Video encoder 200 may adjust the degree of quantization applied to the transform coefficient blocks associated with the current block by adjusting the QP value associated with the CU (eg, via mode select unit 202 ). Quantization may introduce loss of information, and thus, the quantized transform coefficients may have lower precision than the original transform coefficients generated by transform processing unit 206.

Inverse quantization unit 210 and inverse transform processing unit 212 may apply inverse quantization and inverse transforms to the quantized transform coefficient block, respectively, to reconstruct a residual block from the transform coefficient block. Reconstruction unit 214 will generate a reconstructed block corresponding to the current block (potentially with some degree of distortion) based on the predicted block produced by mode select unit 202 and the reconstructed residual block. may be For example, reconstruction unit 214 may add samples of the reconstructed residual block to corresponding samples from the predictive block produced by mode select unit 202 to produce a reconstructed block.

Filter unit 216 may perform one or more filter operations on the reconstructed blocks. For example, filter unit 216 may perform deblocking operations to reduce blockiness artifacts along the edges of CUs. In some examples, operations of filter unit 216 may be skipped.

Video encoder 200 stores the reconstructed blocks in DPB 218 . For example, in examples in which the operations of filter unit 216 have not been performed, reconstruction unit 214 may store the reconstructed blocks to DPB 218 . In examples in which the operations of filter unit 216 are performed, filter unit 216 may store the filtered reconstructed blocks to DPB 218 . Motion estimation unit 222 and motion compensation unit 224 retrieve a reference picture from DPB 218 formed from the reconstructed (and potentially filtered) blocks to inter-block blocks of subsequently encoded pictures. can also be predicted. Intra-prediction unit 226 may also use reconstructed blocks within DPB 218 of the current picture to intra-predict other blocks in the current picture.

In general, entropy encoding unit 220 may entropy encode syntax elements received from other functional components of video encoder 200 . For example, entropy encoding unit 220 may entropy encode the quantized transform coefficient blocks from quantization unit 208 . As another example, entropy encoding unit 220 may entropy encode prediction syntax elements from mode select unit 202 (eg, intra-mode information for intra-prediction or motion information for inter-prediction). may be Entropy encoding unit 220 may perform one or more entropy encoding operations on syntax elements, another example of video data, to generate entropy encoded data. For example, entropy encoding 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 operations, exponential-Golomb encoding operations, or other types of entropy encoding operations may be performed on the data. In some examples, entropy encoding unit 220 may operate in a bypass mode in which syntax elements are not entropy encoded.

Video encoder 200 may output a bitstream that includes entropy encoded syntax elements necessary to reconstruct blocks of a picture or slice. In particular, entropy encoding unit 220 may output a bitstream.

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

In some examples, operations performed on a luma coding block need not be repeated for chroma coding blocks. As an example, operations to identify a motion vector (MV) and reference picture for a luma coding block need not be repeated to identify a reference picture and MV for chroma blocks. Rather, the MV for the luma coding block may be scaled to determine the MV for chroma blocks, and the reference picture may be the same. As another example, the intra-prediction process may be the same for luma coding block and chroma coding blocks.

Video encoder 200 represents an example of a device configured to encode video data comprising a memory configured to store the video data, and one or more processing units implemented in circuitry, the one or more processing units comprising N entries. To construct a general MPM list (N entries of the general MPM list are intra prediction modes, and a plane mode is the ordinal first entry in the general MPM list), construct a primary MPM list from the first Np entries in the general MPM list. (Np is less than N), to construct a secondary MPM list from the remaining (N-Np) entries in the general MPM list, using either the primary MPM list or the secondary MPM list to construct the current block for the current block of video data. Determine an intra prediction mode, and encode a current block of video data using the current intra prediction mode to generate an encoded block of video data.

6 is a block diagram illustrating an example video decoder 300 that may perform the techniques of this disclosure. 6 is provided for purposes of explanation and should not be considered limiting of the techniques as generally exemplified and described in this disclosure. For purposes of explanation, this disclosure describes a video decoder 300 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 video coding devices configured with other video coding standards.

In the example of FIG. 6 , video decoder 300 includes coded picture buffer (CPB) memory 320 , entropy decoding unit 302 , prediction processing unit 304 , inverse quantization unit 306 , inverse transform processing unit 308 , reconstruction unit 310 , filter unit 312 , and decoded picture buffer (DPB) 314 . CPB memory 320, entropy decoding unit 302, prediction processing unit 304, inverse quantization unit 306, inverse transform processing unit 308, reconstruction unit 310, filter unit 312, and DPB ( Any or all of 314) may be implemented in one or more processors or in processing circuitry. For example, the units of video decoder 300 may be implemented as one or more circuits or logic elements as part of hardware circuitry, or as part of a processor, ASIC, or FPGA. Moreover, video decoder 300 may include additional or alternative processors or processing circuitry to perform these and other functions.

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

CPB memory 320 may store video data, such as an encoded video bitstream, to be decoded by the components of video decoder 300 . Video data stored in CPB memory 320 may be obtained, for example, from computer readable medium 110 (FIG. 1). CPB memory 320 may include a CPB that stores encoded video data (eg, syntax elements) from an encoded video bitstream. CPB memory 320 may also store video data other than syntax elements of a coded picture, such as temporary data representing outputs from various units of video decoder 300 . DPB 314 generally stores decoded pictures that video decoder 300 may output and/or use as reference video data when decoding pictures or subsequent data of an encoded video bitstream. CPB memory 320 and DPB 314 may be formed by any of a variety of memory devices, such as DRAM including SDRAM, MRAM, RRAM, or other types of memory devices. CPB memory 320 and DPB 314 may be provided by the same memory device or separate memory devices. In various examples, CPB memory 320 may be on-chip with or off-chip with other components of video decoder 300 .

Additionally or alternatively, in some examples, video decoder 300 may retrieve coded video data from memory 120 (FIG. 1). That is, memory 120 may store data as discussed above with CPB memory 320 . Likewise, memory 120 may store instructions to be executed by video decoder 300 when some or all of the functionality of video decoder 300 is implemented in software executed by processing circuitry of video decoder 300 . .

The various units shown in FIG. 6 are illustrated to aid understanding of the operations performed by video decoder 300 . Units may be implemented as fixed function circuits, programmable circuits, or a combination of both. Similar to FIG. 5, fixed function circuits refer to circuits that provide specific functions and are preset for operations that can be performed. Programmable circuits refer to circuits that can be programmed to perform various tasks and provide flexible functionality in the operations that can be performed. For example, programmable circuits may execute software or firmware that causes the programmable circuits to operate in a manner defined by instructions in the software or firmware. Fixed function circuits may execute software instructions (eg, to receive parameters or output parameters), but the types of operations they perform are generally immutable. In some examples, one or more of the units may be discrete circuit blocks (fixed function or programmable), and in some examples, one or more of the units may be integrated circuits.

Video decoder 300 may include ALUs, EFUs, digital circuits, analog circuits, and/or programmable cores formed from programmable circuits. In examples where the operations of video decoder 300 are performed by software running on programmable circuits, on-chip or off-chip memory may be used to determine the instructions of software that video decoder 300 receives and executes (e.g. For example, object code) may be stored.

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 decoded video data based on syntax elements extracted from the bitstream. can also create

In general, video decoder 300 reconstructs a picture on a block-by-block basis. Video decoder 300 may perform a reconstruction operation on each block individually (where the block currently being reconstructed, ie, being decoded, may be referred to as a “current block”).

Entropy decoding unit 302 may entropy decode syntax elements that define quantized transform coefficients of a quantized transform coefficient block, as well as transform information such as a quantization parameter (QP) and/or transform mode indication(s). . Inverse quantization unit 306 may use the QP associated with the quantized transform coefficient block to determine a degree of quantization and, likewise, a degree of inverse quantization that inverse quantization unit 306 will apply. Inverse quantization unit 306 may, for example, perform a bitwise left-shift operation to inverse quantize the quantized transform coefficients. Inverse quantization unit 306 may thereby form a transform coefficient block that includes transform coefficients.

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

Prediction processing unit 304 also generates a predictive block according to the predictive 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 may generate the predictive block. In this case, the predictive information syntax elements may indicate a motion vector that identifies the location of the reference block in the reference picture relative to the location of the current block in the current picture as well as the reference picture in DPB 314 from which to derive the reference block there is. Motion compensation unit 316 may generally perform the inter-prediction process in a manner substantially similar to that described with respect to motion compensation unit 224 (FIG. 5).

As another example, if the prediction information syntax element indicates that the current block is intra-predicted, intra-prediction unit 318 may generate the predictive block according to the intra-prediction mode indicated by the prediction information syntax elements. . Again, intra-prediction unit 318 may perform the intra-prediction process generally in a manner substantially similar to that described with respect to intra-prediction unit 226 (FIG. 5). Intra-prediction unit 318 may retrieve data of neighboring samples for the current block from DPB 314 .

According to the techniques described above, intra-prediction unit 318 constructs a general MPM list containing N entries (the N entries of the general MPM list are intra prediction modes, and the planar mode is the ordinal number within the general MPM list). 1 entry), constructs a primary MPM list from the first Np entries in the generic MPM list (Np is less than N), constructs a secondary MPM list from the remaining (N-Np) entries in the generic MPM list, , determine a current intra prediction mode for a current block of video data using either the primary MPM list or the secondary MPM list, and use the current intra prediction mode to generate a decoded block of video data. It may also be configured to decode a block.

Reconstruction unit 310 reconstructs a current block using the predictive block and the residual block. For example, reconstruction unit 310 may add samples of the residual pixel block to corresponding samples of the predictive block to reconstruct the current block.

Filter unit 312 may perform one or more filter operations on the reconstructed blocks. For example, filter unit 312 may perform deblocking operations to reduce blockiness artifacts along the edges of reconstructed blocks. Operations of filter unit 312 are not necessarily performed in all examples.

Video decoder 300 may store the reconstructed blocks in DPB 314 . For example, in examples in which the operations of filter unit 312 are not performed, reconstruction unit 310 may store the reconstructed blocks to DPB 314 . In examples in which the operations of filter unit 312 are performed, filter unit 312 may store the filtered reconstructed blocks to DPB 314 . As discussed above, DPB 314 may provide reference information to prediction processing unit 304, such as samples of a current picture for intra-prediction and previously decoded pictures for subsequent motion compensation. . Moreover, video decoder 300 may output decoded pictures (eg, decoded video) from DPB 314 for subsequent presentation on a display device, such as display device 118 of FIG. 1 . there is.

In this way, video decoder 300 represents an example of a video decoding device that includes a memory configured to store video data, and one or more processing units implemented in circuitry, the one or more processing units comprising N entries. To construct a general MPM list (N entries of the general MPM list are intra prediction modes, and a plane mode is the ordinal first entry in the general MPM list), construct a primary MPM list from the first Np entries in the general MPM list. (Np is less than N), to construct a secondary MPM list from the remaining (N-Np) entries in the general MPM list, using either the primary MPM list or the secondary MPM list to construct the current block for the current block of video data. To determine an intra prediction mode, and to decode a current block of video data using the current intra prediction mode to generate a decoded block of video data.

7 is a flowchart illustrating an example method for encoding a current block according to the techniques of this disclosure. A current block may contain a current CU. Although described with respect to video encoder 200 ( FIGS. 1 and 5 ), it should be understood that other devices may be configured to perform a method similar to that of FIG. 7 .

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

8 is a flowchart illustrating an example method for decoding a current block of video data according to the techniques of this disclosure. A current block may contain a current CU. Although described with respect to video decoder 300 ( FIGS. 1 and 6 ), it should be understood that other devices may be configured to perform a method similar to that of FIG. 8 .

Video decoder 300 may receive entropy encoded data for a current block, such as entropy encoded prediction information and entropy encoded data for transform coefficients of a residual block corresponding to the current block ( 370 ). Video decoder 300 may entropy decode the entropy-encoded data to determine prediction information for the current block and reproduce transform coefficients of the residual block ( 372 ). Video decoder 300 may predict a current block to calculate a predictive block for the current block, e.g., using an intra- or inter-prediction mode as indicated by the prediction information for the current block (374 ). Video decoder 300 may then inverse scan the regenerated transform coefficients to produce a block of quantized transform coefficients (376). Video decoder 300 may then inverse quantize the transform coefficients and apply an inverse transform to the transform coefficients to generate a residual block (378). Video decoder 300 may eventually decode the current block by combining the predictive block and the residual block ( 380 ).

9 is a flowchart illustrating another example method for encoding a current block according to the techniques of this disclosure. The techniques of FIG. 9 may be performed by one or more structural units of video encoder 200 , including intra-prediction unit 226 of FIG. 5 .

In one example of this disclosure, video encoder 200 is configured to encode a current block of video data using intra prediction. Video encoder 200 may be configured to build a generic MPM list that includes N entries, where the N entries of the generic MPM list are intra prediction modes and the planar mode is the ordinal first entry in the generic MPM list. (500). Video encoder 200 may also construct a primary MPM list from the first Np entries in the general MPM list, where Np is less than N ( 502 ), and the remainder in the general MPM list (N-Np ) entries may construct a secondary MPM list (504). Video encoder 200 also uses the primary MPM list or the secondary MPM list to determine a current intra prediction mode for a current block of video data ( 506 ) and to generate an encoded block of video data. A prediction mode may be used to encode the current block of video data (508). In one example, N is 22 and Np is 6.

In one example of this disclosure, video encoder 200 may be configured to encode an index into a primary MPM list or a secondary MPM list, where the index is a non-plane in the primary MPM list or secondary MPM list. Indicates intra prediction mode.

In another example of this disclosure, to encode an index into a primary MPM list or a secondary MPM list, video encoder 200 performs entropy encoding of a first bin of the index based on a coding tool used for the current block. It may be configured to determine a context and use the context to entropy encode the first bin of the index. In one example, the coding tool is one of regular intra prediction mode, intra sub-partition mode, or multiple reference line mode.

In another example, to build the general MPM list, video encoder 200 also adds each intra prediction mode from each neighboring block of the current block of video data to the general MPM list, and each neighboring block and add a plurality of intra prediction modes offset from respective intra prediction modes from the general MPM list. Video encoder 200 assigns each intra-prediction mode from each neighboring block of a current block of video data to a generic MPM list, based on which respective intra-prediction modes are available and have not yet been added to the generic MPM list. can also be added to

10 is a flowchart illustrating another example method for decoding a current block according to the techniques of this disclosure. The techniques of FIG. 10 may be performed by one or more structural units of video decoder 300 , including intra-prediction unit 318 of FIG. 6 .

In one example of this disclosure, video decoder 300 may be configured to decode a current block of video data using intra prediction. Video decoder 300 may be configured to build a generic MPM list that includes N entries, where the N entries of the generic MPM list are intra prediction modes and the planar mode is the ordinal first entry in the generic MPM list. (600). Video decoder 300 may also construct a primary MPM list from the first Np entries in the general MPM list, where Np is less than N ( 602 ), and the remainder of the general MPM list (N-Np ) entries may construct a secondary MPM list (604). And, video decoder 300 uses either the primary MPM list or the secondary MPM list to determine a current intra prediction mode for a current block of video data (606), and to generate a decoded block of video data. A prediction mode may be used to decode the current block of video data (608). In one example, N is 22 and Np is 6.

In one example, to determine the current intra prediction mode, video decoder 300 may be further configured to decode an index into the primary MPM list or the secondary MPM list, where the index is the primary MPM list or Indicates a non-planar intra prediction mode in the secondary MPM list. Video decoder 300 may determine a current intra prediction mode for a current block of video data based on the index.

In a further example, to decode an index into a primary MPM list or a secondary MPM list, video decoder 300 adds context for entropy decoding the first bin of the index based on the coding tool used for the current block. , and the first bin of the index may be entropy-decoded using the context. In one example, the coding tool is one of regular intra prediction mode, intra sub-partition mode, or multiple reference line mode.

In another example of this disclosure, to build a general MPM list, video decoder 300 adds each intra prediction modes from each neighboring block of a current block of video data to the general MPM list, and It may also be configured to add a plurality of intra prediction modes offset from respective intra prediction modes from the blocks to the general MPM list. In one example, video decoder 300 determines each intra-prediction mode from each neighboring blocks of a current block of video data, based on which intra-prediction modes are available and have not yet been added to the general MPM list. may be added to the general MPM list.

In another example, to determine a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list, video decoder 300 uses the current MPM from the primary MPM list or secondary MPM list. It may be configured to decode the syntax element indicating the list, decode the index to the current MPM list, and determine the current intra prediction mode from the index to the current MPM list.

Additional aspects of the present disclosure are described below.

Aspect 1A - A coding method of video data, comprising: constructing a general MPM list comprising N entries, wherein the N entries of the general MPM list are intra prediction modes; constructing a primary MPM list from first Np entries in the generic MPM list, where Np is less than N; constructing a secondary MPM list from the remaining (N-Np) entries in the general MPM list; and determining an intra prediction mode for a current block of video data using either the primary MPM list or the secondary MPM list.

Aspect 2A—The method of Embodiment 1A, wherein N is 22 and Np is 6.

Aspect 3A - The method of Aspect 1A or 2A, wherein constructing the general MPM list comprises: adding a planar mode as an ordinal first entry to the general MPM list; adding each of the intra prediction modes from each of the neighboring blocks of the current block of video data to a generic MPM list; and adding intra prediction modes offset from respective intra prediction modes from respective neighboring blocks to the general MPM list.

Aspect 4A - The method of aspect 3A, wherein adding each intra prediction modes from each neighboring block of a current block of video data to the general MPM list comprises: adding to the general MPM list each intra prediction mode from each neighboring block of a current block of video data, if not already added to the list.

Aspect 5A - The method of any one of aspects 1A to 4A, further comprising determining a context for coding an index indicating a non-planar mode of the primary MPM list based on a coding tool used for the current block. How to.

Aspect 6A - The method of aspect 5A, wherein the coding tool is one of regular intra prediction, sub-partitions, or multiple reference lines.

Aspect 7A—The method of any of aspects 1A-6A, wherein coding comprises decoding.

Aspect 8A—The method of any one of aspects 1A-7A, wherein coding comprises encoding.

Aspect 9A - A device for coding video data, comprising one or more means for performing the method of any one of aspects 1A-8A.

Aspect 10A - The device of Aspect 9A, wherein the one or more means comprises one or more processors implemented in circuitry.

Aspect 11A—The device of aspect 9A or 10A, further comprising a memory for storing video data.

Aspect 12A—The device of any of aspects 9A-11A, further comprising a display configured to display the decoded video data.

Aspect 13A - The device of any of Aspects 9A-12A, wherein the device comprises one or more of a camera, computer, mobile device, broadcast receiver device, or set top box.

Aspect 14A - The device of any one of aspects 9A-13A, wherein the device comprises a video decoder.

Aspect 15A - The device of any of aspects 9A-14A, wherein the device comprises a video encoder.

Aspect 16A - A computer readable storage medium having stored thereon instructions which, when executed, cause one or more processors to perform the method of any one of aspects 1A-8A.

Aspect 1B - A decoding method of video data, comprising constructing a generic MPM list containing N entries, wherein the N entries of the generic MPM list are intra prediction modes, and a planar mode is an ordinal first entry in the generic MPM list. ; constructing a primary MPM list from first Np entries in the general MPM list, where Np is less than N; constructing a secondary MPM list from the remaining (N-Np) entries in the general MPM list; determining a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list; and decoding a current block of video data using a current intra prediction mode to produce a decoded block of video data.

Aspect 2B - The method of aspect 1B, wherein the determining of the current intra prediction mode comprises: an index indicating a non-planar intra prediction mode in the primary MPM list or the secondary MPM list, in the primary MPM list or the secondary MPM list; decoding into a secondary MPM list; and determining a current intra prediction mode for a current block of video data based on the index.

Aspect 3B - The method of aspect 2B, wherein decoding the index into the primary MPM list or the secondary MPM list comprises: entropy decoding a first bin of the index based on a coding tool used for a current block. determining the context; and entropy decoding a first bin of the index using the context.

Aspect 4B—The method of aspect 3B, wherein the coding tool is one of regular intra prediction mode, intra sub-partition mode, or multiple reference line mode.

Aspect 5B—The method of Embodiment 1B, wherein N is 22 and Np is 6.

Aspect 6B - The method of aspect 1B, wherein constructing the general MPM list comprises: adding each intra prediction mode from each neighboring block of the current block of video data to the general MPM list; and adding a plurality of intra prediction modes offset from respective intra prediction modes from respective neighboring blocks to a general MPM list.

Aspect 7B - The method of aspect 6B, wherein adding each intra prediction modes from each neighboring block of a current block of video data to the general MPM list comprises determining whether the respective intra prediction modes are available and the general MPM adding each of the intra prediction modes from each neighboring blocks of a current block of video data to the general MPM list, based on not yet being added to the list.

Aspect 8B - The method of aspect 1B, wherein determining a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list comprises: Decoding a syntax element indicating ; decoding the index for the current MPM list; and determining a current intra prediction mode from the index to the current MPM list.

Aspect 9B—The method of aspect IB, further comprising displaying a picture comprising the decoded block of video data.

Aspect 10B - An apparatus configured to decode video data, the apparatus comprising: a memory configured to store a current block of video data; and one or more processors implemented in circuitry and in communication with the memory, the one or more processors constructing a generic MPM list comprising N entries, wherein the N entries of the generic MPM list are intra prediction modes and , construct the general MPM list, wherein the plane mode is the ordinal first entry in the general MPM list; construct a primary MPM list from first Np entries in the general MPM list, wherein Np is less than N; construct a secondary MPM list from the remaining (N-Np) entries in the general MPM list; determine a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list; and decode a current block of video data using the current intra prediction mode to produce a decoded block of video data.

Aspect 11B - The method of aspect 10B, wherein to determine the current intra prediction mode, the one or more processors further determine an index indicating a non-planar intra prediction mode in the primary MPM list or the secondary MPM list. decoding into the primary MPM list or the secondary MPM list; and determine a current intra prediction mode for a current block of video data based on the index.

Aspect 12B - The method of aspect 1 IB, wherein to decode the index into the primary MPM list or the secondary MPM list, the one or more processors further: based on a coding tool used for a current block, the first MPM list of the index to determine a context for entropy decoding a bin; and

and entropy decode a first bin of the index using the context.

Aspect 13B-The apparatus of aspect 12B, wherein the coding tool is one of regular intra prediction mode, intra sub-partition mode, or multiple reference line mode.

Aspect 14B—The apparatus of aspect 10B, wherein N is 22 and Np is 6.

Aspect 15B - The method of aspect 10B, wherein to construct the general MPM list, the one or more processors are further configured to add to the general MPM list each intra prediction mode from each neighboring block of a current block of video data. ; and add a plurality of intra prediction modes offset from respective intra prediction modes from respective neighboring blocks to the general MPM list.

Aspect 16B - The method of aspect 15B, wherein to add each intra prediction modes from each neighboring block of a current block of video data to the general MPM list, the one or more processors further: and add respective intra prediction modes from respective neighboring blocks of a current block of video data to the general MPM list, based on being available and not yet added to the general MPM list.

Aspect 17B - The method of aspect 10B, wherein to determine a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list, the one or more processors further: or decoding a syntax element indicating a current MPM list from the secondary MPM list; decode the index for the current MPM list; and determine a current intra prediction mode from the index to the current MPM list.

Aspect 18B—The apparatus of aspect 10B, further comprising a display configured to display a picture comprising a decoded block of video data.

Aspect 19B - An apparatus configured to decode video data, means for constructing a generic MPM list comprising N entries, wherein the N entries of the generic MPM list are intra prediction modes, and a planar mode is an ordinal number 1 in the generic MPM list. entry); means for constructing a primary MPM list from first Np entries in the generic MPM list, where Np is less than N; means for constructing a secondary MPM list from remaining (N-Np) entries in the general MPM list; means for determining a current intra prediction mode for a current block of video data using either the primary MPM list or the secondary MPM list; and means for decoding a current block of video data using a current intra prediction mode to produce a decoded block of video data.

Aspect 20B - The method of aspect 19B, wherein the means for determining the current intra prediction mode comprises an index indicative of a non-planar intra prediction mode in the primary MPM list or the secondary MPM list; means for decoding into the secondary MPM list; and means for determining a current intra prediction mode for a current block of video data based on the index.

Aspect 21B - The method of aspect 20B, wherein the means for decoding the index into the primary MPM list or the secondary MPM list comprises entropy decoding a first bin of the index based on a coding tool used for a current block. means for determining a context for a game; and means for entropy decoding a first bin of the index using the context.

Aspect 22B - a non-transitory computer-readable storage medium storing instructions that, when executed, cause one or more processors configured to decode video data to construct a generic MPM list comprising N entries, wherein the construct the general MPM list, wherein the N entries of the general MPM list are intra prediction modes, and a planar mode is an ordinal first entry in the general MPM list; construct a primary MPM list from first Np entries in the general MPM list, wherein Np is less than N; construct a secondary MPM list from the remaining (N-Np) entries in the general MPM list; determine a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list; and decoding a current block of video data using the current intra prediction mode to produce a decoded block of video data.

Aspect 23B - The method of aspect 22B, wherein to determine the current intra prediction mode, the instructions further cause the one or more processors to select a non-planar intra prediction mode in the primary MPM list or the secondary MPM list. decoding an index indicating ? into the primary MPM list or the secondary MPM list; and determine a current intra prediction mode for a current block of video data based on the index.

Aspect 24B - The method of aspect 23B, wherein to decode the index into the primary MPM list or the secondary MPM list, the instructions further cause the one or more processors to: to determine a context for entropy decoding a first bin of the index; and use the context to entropy decode a first bin of the index.

Aspect 25B - An apparatus configured to encode video data, the apparatus comprising: a memory configured to store a current block of video data; and one or more processors implemented in circuitry and in communication with the memory, the one or more processors constructing a generic MPM list comprising N entries, wherein the N entries of the generic MPM list are intra prediction modes and , construct the general MPM list, wherein the plane mode is the ordinal first entry in the general MPM list; construct a primary MPM list from first Np entries in the general MPM list, wherein Np is less than N; construct a secondary MPM list from the remaining (N-Np) entries in the general MPM list; determine a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list; and encode a current block of video data using the current intra prediction mode to generate an encoded block of video data.

Aspect 26B - The apparatus of aspect 25B, wherein the one or more processors further assign an index indicating a non-planar intra prediction mode in the primary MPM list or the secondary MPM list to the primary MPM list or the secondary MPM list. An apparatus configured to encode to.

Aspect 27B - The method of aspect 26B, wherein to encode the index into the primary MPM list or the secondary MPM list, the one or more processors further: based on a coding tool used for a current block, the first MPM list of the index to determine a context for entropy encoding a bin; and entropy encode a first bin of the index using the context.

Aspect 28B - The apparatus of aspect 27B, wherein the coding tool is one of regular intra prediction mode, intra sub-partition mode, or multiple reference line mode.

Aspect 29B—The apparatus of aspect 25B, wherein N is 22 and Np is 6.

Aspect 30B - Aspect 25B, wherein to construct the general MPM list, the one or more processors are further configured to add to the general MPM list each intra prediction mode from each neighboring block of a current block of video data. ; and add a plurality of intra prediction modes offset from respective intra prediction modes from respective neighboring blocks to the general MPM list.

Aspect 31B - The method of aspect 25B, wherein to add each intra prediction modes from each neighboring block of a current block of video data to the general MPM list, the one or more processors further: and add respective intra prediction modes from respective neighboring blocks of a current block of video data to the general MPM list, based on being available and not yet added to the general MPM list.

Aspect 32B - The apparatus of aspect 25B, further comprising a camera configured to capture a picture comprising a current block of video data.

Aspect 1C - A method of decoding video data, comprising: constructing a generic MPM list containing N entries, wherein the N entries of the generic MPM list are intra prediction modes, and the planar mode is the ordinal first entry in the generic MPM list. ; constructing a primary MPM list from first Np entries in the general MPM list, where Np is less than N; constructing a secondary MPM list from the remaining (N-Np) entries in the general MPM list; determining a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list; and decoding a current block of video data using a current intra prediction mode to produce a decoded block of video data.

Aspect 2C - In aspect 1C, the determining of the current intra prediction mode comprises setting an index indicating a non-planar intra prediction mode in the primary MPM list or the secondary MPM list to the primary MPM list or the secondary MPM list. decoding into a secondary MPM list; and determining a current intra prediction mode for a current block of video data based on the index.

Aspect 3C - The method of aspect 2C, wherein decoding the index into the primary MPM list or the secondary MPM list comprises: entropy decoding a first bin of the index based on a coding tool used for a current block. determining the context; and entropy decoding a first bin of the index using the context.

Aspect 4C—The method of aspect 3C, wherein the coding tool is one of regular intra prediction mode, intra sub-partition mode, or multiple reference line mode.

Aspect 5C—The method of any one of Aspects 1C to 4C, wherein N is 22 and Np is 6.

Aspect 6C - The method of any one of aspects 1C to 5C, wherein constructing the general MPM list comprises: adding each intra prediction mode from each neighboring block of the current block of video data to the general MPM list; and adding a plurality of intra prediction modes offset from respective intra prediction modes from respective neighboring blocks to a general MPM list.

Aspect 7C - The method of aspect 6C, wherein adding each intra prediction modes from each neighboring block of a current block of video data to the general MPM list comprises: adding each of the intra prediction modes from each neighboring blocks of a current block of video data to the general MPM list, based on not yet being added to the list.

Aspect 8C - The method of any one of aspects 1C to 7C, wherein determining a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list comprises: decoding a syntax element indicating a current MPM list from the MPM list; decoding the index for the current MPM list; and determining a current intra prediction mode from the index to the current MPM list.

Aspect 9C—The method of any one of aspects 1C-8C, further comprising displaying a picture comprising the decoded block of video data.

Aspect 10C - An apparatus configured to decode video data, the apparatus comprising: a memory configured to store a current block of video data; and one or more processors implemented in circuitry and in communication with the memory, the one or more processors constructing a generic MPM list comprising N entries, wherein the N entries of the generic MPM list are intra prediction modes and , construct the general MPM list, wherein the plane mode is the ordinal first entry in the general MPM list; construct a primary MPM list from first Np entries in the general MPM list, wherein Np is less than N; construct a secondary MPM list from the remaining (N-Np) entries in the general MPM list; determine a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list; and decode a current block of video data using the current intra prediction mode to produce a decoded block of video data.

Aspect 11C - The apparatus of aspect 10C, wherein to determine the current intra prediction mode, the one or more processors further determine an index indicating a non-planar intra prediction mode in the primary MPM list or the secondary MPM list. decoding into the primary MPM list or the secondary MPM list; and determine a current intra prediction mode for a current block of video data based on the index.

Aspect 12C - The method of aspect 11C, wherein to decode the index into the primary MPM list or the secondary MPM list, the one or more processors further: based on a coding tool used for a current block of video data, the index determine a context for entropy decoding a first bin of ; and

and entropy decode a first bin of the index using the context.

Aspect 13C—The apparatus of aspect 12C, wherein the coding tool is one of regular intra prediction mode, intra sub-partition mode, or multiple reference line mode.

Aspect 14C—The apparatus of any one of Aspects 10C-13C, wherein N is 22 and Np is 6.

Aspect 15C - The method of any of aspects 10C to 14C, wherein to construct the general MPM list, the one or more processors further select respective intra prediction modes from respective neighboring blocks of a current block of video data. to add to the general MPM list; and add a plurality of intra prediction modes offset from respective intra prediction modes from respective neighboring blocks to the general MPM list.

Aspect 16C - The method of aspect 15C, wherein to add each intra prediction modes from each neighboring block of a current block of video data to the general MPM list, the one or more processors further: and add respective intra prediction modes from respective neighboring blocks of a current block of video data to the general MPM list, based on being available and not yet added to the general MPM list.

Aspect 17C - The method of any of aspects 10C to 16C, wherein to determine a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list, the one or more processors further: , decoding a syntax element indicating a current MPM list from the primary MPM list or the secondary MPM list; decode the index for the current MPM list; and determine a current intra prediction mode from the index to the current MPM list.

Aspect 18C—The apparatus of any of aspects 10C-17C, further comprising a display configured to display a picture comprising a decoded block of video data.

Aspect 19C - An apparatus configured to encode video data, the apparatus comprising: a memory configured to store a current block of video data; and one or more processors implemented in circuitry and in communication with the memory, the one or more processors constructing a generic MPM list comprising N entries, wherein the N entries of the generic MPM list are intra prediction modes and , construct the general MPM list, wherein the plane mode is the ordinal first entry in the general MPM list; construct a primary MPM list from first Np entries in the general MPM list, wherein Np is less than N; construct a secondary MPM list from the remaining (N-Np) entries in the general MPM list; determine a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list; and encode a current block of video data using the current intra prediction mode to generate an encoded block of video data.

Aspect 20C - The method of aspect 19C, wherein the one or more processors further assign an index indicating a non-planar intra prediction mode in the primary MPM list or the secondary MPM list to the primary MPM list or the secondary MPM list. An apparatus configured to encode to.

Aspect 21C - The apparatus of aspect 20C, wherein to encode the index into the primary MPM list or the secondary MPM list, the one or more processors further: based on a coding tool used for a current block of video data, the index determine a context for entropy decoding a first bin of ; and entropy encode a first bin of the index using the context.

Aspect 22C - The method of aspect 21C, wherein the coding tool is in regular intra prediction mode, A device that is either in intra sub-partition mode, or multiple reference line mode.

Aspect 23C—The apparatus of any one of Aspects 19C-22C, wherein N is 22 and Np is 6.

Aspect 24C - The method of any of aspects 19C to 23C, wherein to construct the general MPM list, the one or more processors further select respective intra prediction modes from respective neighboring blocks of a current block of video data to: to add to the general MPM list; and add a plurality of intra prediction modes offset from respective intra prediction modes from respective neighboring blocks to the general MPM list.

Aspect 25 - The method of any of aspects 19C to 24C, wherein the one or more processors further: to add each intra prediction modes from each neighboring block of a current block of video data to the general MPM list. Add each intra prediction mode from each neighboring block of a current block of video data to the general MPM list, based on which respective intra prediction modes are available and have not yet been added to the general MPM list. , Device.

Aspect 26C—The apparatus of any of aspects 19C-25C, further comprising a camera configured to capture a picture comprising a current block of video data.

Depending on the example, certain acts or events of any of the techniques described herein may be performed in a different sequence, and may be added, merged, or omitted altogether (e.g., all described acts It should be appreciated that the events or events are not required for practice of the techniques. Moreover, in certain examples, acts or events may be performed simultaneously rather than sequentially, for example via multi-threaded processing, interrupt processing, or multiple processors.

In one or more examples, the described functions may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer readable medium and executed by a hardware-based processing unit. Computer readable media are computer readable storage media that correspond to tangible media such as data storage media, or any medium that facilitates transfer of a computer program from one place to another, eg, according to a communication protocol. It may also include communication media including. In this manner, computer-readable media generally may correspond to (1) tangible computer-readable storage media that is non-transitory 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, code and/or data structures for implementation of the techniques described in this disclosure. A computer program product may include a computer readable medium.

By way of example and not limitation, such computer readable storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage, or other magnetic storage devices, flash memory, or instructions or data structures. can include any other medium that can be used to store desired program code in the form of s and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the instructions are transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, coaxial Cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. However, it should be understood that computer readable storage media and data storage media do not include connections, carrier waves, signals, or other transitory media, but are instead directed to non-transitory tangible storage media. As used herein, disk and disc include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy discs, and Blu-ray discs, wherein Disks usually reproduce data magnetically, while discs reproduce data optically using lasers. Combinations of the above should also be included within the scope of computer-readable media.

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 circuitry. Accordingly, the terms “processor” and “processing circuitry” as used herein may refer to any of the foregoing structures or any other structure suitable for implementation of the techniques described herein. Additionally, in some aspects, the functionality described herein may be provided within dedicated hardware and/or software modules configured for encoding and decoding, or integrated into a combined codec. Also, the techniques could be fully implemented in one or more circuits or logic elements.

The techniques of this disclosure may be implemented in a wide variety of devices or apparatuses, including a wireless handset, an integrated circuit (IC) or set of ICs (eg, a chip set). Various components, modules, or units are described in this disclosure to emphasize functional aspects of devices configured to perform the disclosed techniques, but do not necessarily require realization by different hardware units. Rather, as described above, the various units may be coupled to a codec hardware unit, or provided by a collection of interoperable hardware units including one or more processors as described above, in conjunction with suitable software and/or firmware. It could be.

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

Claims (32)

A method of decoding video data, the method comprising:
Constructing a general most probable mode (MPM) list containing N entries, wherein the N entries of the general MPM list are intra prediction modes, and a plane mode is an ordinal number in the general MPM list ( ordinal) constructing the general MPM list, which is a first entry;
constructing a primary MPM list from first Np entries in the general MPM list, wherein Np is less than N;
constructing a secondary MPM list from the remaining (N-Np) entries in the general MPM list;
determining a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list; and
decoding a current block of video data using the current intra prediction mode to produce a decoded block of video data. According to claim 1,
The step of determining the current intra prediction mode,
decoding an index indicating a non-planar intra prediction mode in the primary MPM list or the secondary MPM list into the primary MPM list or the secondary MPM list; and
determining a current intra prediction mode for a current block of video data based on the index. According to claim 2,
Decoding the index into the primary MPM list or the secondary MPM list,
determining a context for entropy decoding a first bin of the index based on a coding tool used for a current block of video data; and
entropy decoding a first bin of the index using the context. According to claim 3,
wherein the coding tool is one of regular intra prediction mode, intra sub-partition mode, or multiple reference line mode. According to claim 1,
wherein N is 22 and Np is 6. According to claim 1,
The step of constructing the general MPM list,
adding each of the intra prediction modes from each of the neighboring blocks of the current block of video data to the general MPM list; and
and adding a plurality of intra prediction modes offset from respective intra prediction modes from respective neighboring blocks to the general MPM list. According to claim 6,
Adding each intra prediction mode from each neighboring block of the current block of video data to the general MPM list is based on the respective intra prediction modes being available and not yet added to the general MPM list. and adding each of the intra prediction modes from each of the neighboring blocks of the current block of video data to the general MPM list. According to claim 1,
The step of determining a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list,
decoding a syntax element indicating a current MPM list from the primary MPM list or the secondary MPM list;
decoding the index for the current MPM list; and
determining a current intra prediction mode from the index to the current MPM list. According to claim 1,
The method further comprising displaying a picture comprising the decoded block of video data. A device configured to decode video data, the device comprising:
a memory configured to store a current block of video data; and
One or more processors implemented in circuitry and in communication with the memory.
Including, the one or more processors,
Constructing a general MPM list including N entries, wherein the N entries of the general MPM list are intra prediction modes, and a plane mode is an ordinal first entry in the general MPM list; ;
construct a primary MPM list from first Np entries in the general MPM list, wherein Np is less than N;
construct a secondary MPM list from the remaining (N-Np) entries in the general MPM list;
determine a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list;
Decode a current block of video data using the current intra prediction mode to produce a decoded block of video data.
configured device. According to claim 10,
To determine the current intra prediction mode, the one or more processors also:
decoding an index indicating a non-planar intra prediction mode in the primary MPM list or the secondary MPM list into the primary MPM list or the secondary MPM list;
determine a current intra prediction mode for a current block of video data based on the index;
configured device. According to claim 11,
To decode the index into the primary MPM list or the secondary MPM list, the one or more processors also:
determine a context for entropy decoding a first bin of the index based on a coding tool used for a current block of video data;
To entropy decode a first bin of the index using the context
configured device. According to claim 12,
wherein the coding tool is one of regular intra prediction mode, intra sub-partition mode, or multiple reference line mode. According to claim 10,
N is 22 and Np is 6. According to claim 10,
To construct the generic MPM list, the one or more processors also:
add each intra prediction mode from each neighboring block of the current block of video data to the general MPM list;
To add a plurality of intra prediction modes offset from respective intra prediction modes from respective neighboring blocks to the general MPM list
configured device. According to claim 15,
To add each intra prediction mode from each neighboring block of the current block of video data to the general MPM list, the one or more processors also: and add each intra prediction mode from each neighboring block of a current block of video data to the general MPM list based on one not yet added. According to claim 10,
To determine a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list, the one or more processors also:
decoding a syntax element indicating a current MPM list from the primary MPM list or the secondary MPM list;
decode the index for the current MPM list;
To determine a current intra prediction mode from the index to the current MPM list
configured device. According to claim 10,
The apparatus further comprising a display configured to display a picture comprising a decoded block of video data. A device configured to decode video data, the device comprising:
Means for constructing a general MPM list comprising N entries, wherein the N entries of the general MPM list are intra prediction modes, and a plane mode is an ordinal first entry in the general MPM list. means for configuring;
means for constructing a primary MPM list from first Np entries in the general MPM list, wherein Np is less than N;
means for constructing a secondary MPM list from remaining (N-Np) entries in the general MPM list;
means for determining a current intra prediction mode for a current block of video data using either the primary MPM list or the secondary MPM list; and
means for decoding a current block of video data using the current intra prediction mode to produce a decoded block of video data. According to claim 19,
The means for determining the current intra prediction mode comprises:
means for decoding an index indicating a non-planar intra prediction mode in the primary MPM list or the secondary MPM list into the primary MPM list or the secondary MPM list; and
means for determining a current intra prediction mode for a current block of video data based on the index. 21. The method of claim 20,
Means for decoding the index into the primary MPM list or the secondary MPM list comprises:
means for determining a context for entropy decoding a first bin in the index based on a coding tool used for a current block of video data; and
means for entropy decoding a first bin of the index using the context. A non-transitory computer-readable storage medium storing instructions,
The instructions, when executed, cause one or more processors configured to decode video data to:
Constructing a general MPM list including N entries, wherein the N entries of the general MPM list are intra prediction modes, and a plane mode is an ordinal first entry in the general MPM list; ;
construct a primary MPM list from first Np entries in the general MPM list, wherein Np is less than N;
construct a secondary MPM list from the remaining (N-Np) entries in the general MPM list;
determine a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list;
and decoding a current block of video data using the current intra prediction mode to produce a decoded block of video data. 23. The method of claim 22,
To determine the current intra prediction mode, the instructions also cause the one or more processors to:
decoding an index indicating a non-planar intra prediction mode in the primary MPM list or the secondary MPM list into the primary MPM list or the secondary MPM list;
and determine a current intra prediction mode for a current block of video data based on the index. 24. The method of claim 23,
To decode the index into the primary MPM list or the secondary MPM list, the instructions also cause the one or more processors to:
determine a context for entropy decoding a first bin of the index based on a coding tool used for a current block of video data;
and use the context to entropy decode a first bin of the index. A device configured to encode video data, the device comprising:
a memory configured to store a current block of video data; and
One or more processors implemented in circuitry and in communication with the memory.
Including, the one or more processors,
Constructing a general MPM list including N entries, wherein the N entries of the general MPM list are intra prediction modes, and a plane mode is an ordinal first entry in the general MPM list; ;
construct a primary MPM list from first Np entries in the general MPM list, wherein Np is less than N;
construct a secondary MPM list from the remaining (N-Np) entries in the general MPM list;
determine a current intra prediction mode for a current block of video data using the primary MPM list or the secondary MPM list;
Decode a current block of video data using the current intra prediction mode to produce a decoded block of video data.
configured device. 26. The method of claim 25,
The one or more processors are further configured to encode an index indicating a non-planar intra prediction mode in the primary MPM list or the secondary MPM list into the primary MPM list or the secondary MPM list. 17. The method of claim 16,
To encode the index into the primary MPM list or the secondary MPM list, the one or more processors also:
determine a context for entropy encoding a first bin in the index based on a coding tool used for a current block of video data;
To entropy encode a first bin of the index using the context
configured device. 28. The method of claim 27,
wherein the coding tool is one of regular intra prediction mode, intra sub-partition mode, or multiple reference line mode. 26. The method of claim 25,
N is 22 and Np is 6. 26. The method of claim 25,
To construct the generic MPM list, the one or more processors also:
add each intra prediction mode from each neighboring block of the current block of video data to the general MPM list;
To add a plurality of intra prediction modes offset from respective intra prediction modes from respective neighboring blocks to the general MPM list
configured device. 26. The method of claim 25,
To add each intra prediction mode from each neighboring block of the current block of video data to the general MPM list, the one or more processors also: and add each intra prediction mode from each neighboring block of a current block of video data to the general MPM list based on one not yet added. 26. The method of claim 25,
The apparatus further comprising a camera configured to capture a picture comprising a current block of video data.