JP2024501138A - Most probable mode for intra prediction in video coding - Google Patents

Abstract

A video coder may code a block of video data using an intra prediction mode determined from a most probable mode list. The video coder is to construct a total most probable mode list containing N entries, where N entries of the total most probable mode list are intra prediction modes, and planar modes are among the total most probable mode list. and constructing a first-order most probable mode list from the first Np entries in the total most probable mode list, where Np is less than N. and constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list. The video coder may then determine the current intra-prediction mode for the current block of video data using the first-order most probable mode list or the second-order most probable mode list.

Description

This application claims priority to, and is based on, U.S. Application 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 these applications are incorporated herein by reference. U.S. Application 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.

TECHNICAL FIELD This disclosure relates to video encoding and video decoding.

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

Video coding techniques include spatial (intra-picture) prediction and/or temporal (inter-picture) prediction to reduce or eliminate redundancy inherent in video sequences. For block-based video coding, a video slice (e.g., a video picture or a portion of a video picture) may be partitioned into video blocks, which include coding tree units (CTUs), coding units (CUs) and/or video blocks. Also called a coding node. Video blocks in intra-coded (I) slices of a picture are encoded using spatial prediction on reference samples in adjacent blocks in 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 adjacent blocks in the same picture or temporal prediction with respect to reference samples in other reference pictures. A picture is sometimes called a frame, and a reference picture is sometimes called a reference frame.

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: Via Teleconference, June 22nd to July 1st, 2020, JVET-S2001-vA J. Chen, Y. Ye, and S.-H. Kim, “Algorithm description for Versatile Video Coding and Test Model 9 (VTM 9),” JVET-R2002, April 2020. A. Ramasubramonian et al., “CE3-3.1.1: Two MPM modes and shape dependency (Test 3.1.1),” Joint Video Exploration Team of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29/WG 11. (JVET), 11th Conference: Ljubljana, Slovenia, July 10-18, 2018

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 most probable mode 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 total most probable mode list and then constructing a first order most probable mode list and a second order most probable mode list from the total most probable mode list. The first most probable mode list and the second most probable mode list may include intra prediction modes from neighboring blocks as well as intra prediction modes offset from the intra prediction modes of neighboring blocks. The techniques of this disclosure may improve the efficiency of generating first-order most probable mode lists and second-order most probable mode lists.

In one example, the method includes constructing a total most probable mode list including N entries, wherein N entries of the total most probable mode list are intra-predicted modes and planar modes are in the total most probable mode list. and constructing a first-order most probable mode list from the first Np entries in the total most probable mode list, where Np is less than N. and constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list; determining a current intra prediction mode for the current block of data; and decoding the current block of video data using the current intra prediction mode to produce a decoded block of video data. including.

In another example, the device has a memory and constructs a total most probable mode list including N entries, wherein N entries of the total most probable mode list are intra-predicted modes and the planar modes are the first entry in the total most probable mode list, and constructing a first order most probable mode list from the first Np entries in the total most probable mode list, the first order most probable mode list being Np is less than N, constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list, and constructing a quadratic most probable mode list or a quadratic most probable mode list Determining the current intra prediction mode for the current block of video data using the most probable mode list and using the current intra prediction mode to generate the decoded block of video data and one or more processors configured to decode the current block of data.

In another example, the device is means for constructing a total most probable mode list including N entries, wherein N entries of the total most probable mode list are intra-predicted modes and the planar modes are total a first entry in the most probable mode list; and means for constructing a first order most probable mode list from the first Np entries in the total most probable mode list, where Np is the first entry in the most probable mode list; means for constructing a second-order most probable mode list from the remaining (N-Np) entries in the total most probable mode list, and a first-order most probable mode list or a second-order most probable mode list, means for determining a current intra-prediction mode for a current block of video data using a mode list; and using the current intra-prediction mode to generate a decoded block of video data. and means for decoding the current block of video data.

In another example, the non-transitory computer-readable storage medium, when executed, causes the programmable processor to construct a total most probable mode list including N entries, the N entries of the total most probable mode list. is the intra-prediction mode, and the planar mode is the first entry in the total most probable mode list. Constructing a definite mode list, where Np is less than N, and constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list. determining a current intra-prediction mode for a current block of video data using a first-order most probable mode list or a second-order most probable mode list; and generating a decoded block of video data. and decode the current block of video data using the current intra-prediction mode.

In another example, the device has a memory and constructs a total most probable mode list including N entries, wherein N entries of the total most probable mode list are intra-predicted modes and the planar modes are the first entry in the total most probable mode list, and constructing a first order most probable mode list from the first Np entries in the total most probable mode list, where Np is less than N, constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list, and constructing a quadratic most probable mode list or a quadratic most probable mode list determining a current intra-prediction mode for the current block of video data using the most probable mode list and using the current intra-prediction mode to generate an encoded block of video data; and one or more processors 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 be apparent from the description, drawings, and claims.

FIG. 1 is a block diagram illustrating an example video encoding and decoding system that may implement techniques of this disclosure. FIG. 3 is a conceptual diagram illustrating an example of adjacent blocks used to derive a most probable mode list. FIG. 7 is a conceptual diagram illustrating another example of adjacent blocks used to derive a most probable mode list. FIG. 2 is a conceptual diagram showing an exemplary quadtree binary tree (QTBT) structure. FIG. 2 is a conceptual diagram showing a corresponding coding tree unit (CTU). FIG. 1 is a block diagram illustrating an example video encoder that may implement techniques of this disclosure. 1 is a block diagram illustrating an example video decoder that may implement techniques of this disclosure. FIG. 2 is a flowchart illustrating an example method for encoding a current block in accordance with techniques of this disclosure. 3 is a flowchart illustrating an example method for decoding a current block in accordance with techniques of this disclosure. 5 is a flowchart illustrating another example method for encoding a current block in accordance with techniques of this disclosure. 3 is a flowchart illustrating another example method for decoding a current block in accordance with the techniques of this disclosure.

Versatile Video Coding (VVC) was developed by the ITU-T and ISO/IEC Joint Video Experts Team (JVET) to provide substantial compression capabilities over HEVC for a wide range of applications. The VVC specification was finalized in July 2020 and published by both ITU-T and ISO/IEC. The VVC specification specifies normative bitstream and picture formats, high-level syntax (HLS) and coding unit-level syntax, and parsing and decoding processes. VVC also specifies Profile/Tier/Level (PTL) restrictions, byte stream formats, virtual reference decoders, and Supplemental Enhancement Information (SEI) in the Annex.

In general, this disclosure describes techniques for determining a most probable mode list for intra prediction and determining an intra prediction mode from the most probable mode list. The techniques of this disclosure may improve the efficiency of generating first-order most probable mode lists and second-order most probable mode lists. For example, the video encoder and/or video decoder may construct a total most probable mode list containing N entries, where N entries of the total most probable mode list are intra-prediction modes. and constructing a first-order most probable mode list from the first Np entries in the total most probable mode list, where Np is less than N; and intra-prediction for the current block of video data using the first-order most probable mode list or the second-order most probable mode list from the remaining (N-Np) entries. and determining a mode.

FIG. 1 is a block diagram illustrating an example video encoding and decoding system 100 that may implement the techniques of this disclosure. The techniques of this disclosure are generally directed 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, in this example, a source device 102 that provides encoded video data to be decoded and displayed by a destination device 116. Specifically, source device 102 provides video data to destination device 116 via computer-readable medium 110. Source device 102 and destination device 116 may include desktop computers, notebook (i.e., laptop) computers, mobile devices, tablet computers, set-top boxes, telephone handsets such as smartphones, televisions, cameras, display devices, digital media players, It may include any of a wide variety of devices, including 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 video source 104, memory 106, video encoder 200, and output interface 108. Destination device 116 includes input interface 122, video decoder 300, memory 120, and display device 118. In accordance with 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 a most probable mode list for intra prediction. Thus, source device 102 represents an example of a video encoding device, and destination device 116 represents an example of a video decoding device. In other examples, the source device and destination device may include other components or configurations. For example, source device 102 may receive video data from an external video source, such as an external camera. Similarly, destination device 116 may interface with an external display device rather than including an integrated display device.

A system 100 as shown in FIG. 1 is only one example. In general, any digital video encoding and/or decoding device may implement techniques for deriving a most probable mode list for intra prediction. Source device 102 and destination device 116 are only examples of coding devices such that source device 102 generates coded video data for transmission to destination device 116. This disclosure refers to a device that performs coding (encoding and/or decoding) of data as a "coding" device. Accordingly, video encoder 200 and video decoder 300 represent examples of coding devices, specifically video encoders and video decoders, respectively. In some examples, source device 102 and destination device 116 may operate in a substantially symmetrical manner such that each of source device 102 and destination device 116 includes video encoding and decoding components. Thus, system 100 may support one-way or two-way video transmission between source device 102 and destination device 116, for example, for video streaming, video playback, video broadcasting, or video telephony.

Generally, video source 104 represents a source of video data (i.e., raw, unencoded video data) that provides a continuous series of pictures (also referred to as “frames”) of video data to video encoder 200. , video encoder 200 encodes data for pictures. Video source 104 of source device 102 may include a video capture device, such as a video camera, a video archive containing previously captured raw video, and/or a video feed interface for receiving video from a video content provider. . As a further alternative, video source 104 may produce computer graphics-based data as the source video, or a combination of live, archived, and computer-generated video. In each case, video encoder 200 encodes captured, pre-captured, or computer-generated video data. Video encoder 200 may reorder pictures from a received order (sometimes referred to as a "display order") to a coding order for coding. Video encoder 200 may generate a bitstream that includes encoded video data. Source device 102 may then output the encoded video data via output interface 108 onto computer-readable medium 110, for example, 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 memory. In some examples, memories 106, 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, 120 may store software instructions executable by video encoder 200 and video decoder 300, respectively, for example. Although memory 106 and memory 120 are shown separately from video encoder 200 and video decoder 300 in this example, video encoder 200 and video decoder 300 also include internal memory for functionally similar or equivalent purposes. I hope you understand what you get. Additionally, memories 106, 120 may store encoded video data, such as output from video encoder 200 and input to video decoder 300. In some examples, a portion of memory 106, 120 is allocated as one or more video buffers, e.g., for storing raw, decoded, and/or encoded video data. obtain.

Computer-readable medium 110 may represent any type of medium or device that can transport encoded video data from source device 102 to destination device 116. In one example, computer-readable medium 110 is a communication medium that enables source device 102 to transmit encoded video data directly to destination device 116 in real-time, such as over a radio frequency network or a computer-based network. represents. Output interface 108 may modulate the transmitted signal containing encoded video data and input interface 122 may demodulate the received transmitted signal in accordance with a communication standard, such as a wireless communication protocol. A communication medium may comprise 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, wide area network, or global network such as the Internet. Communication media may include routers, switches, base stations, or any other equipment that may be useful for facilitating 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 include a hard drive, Blu-ray disc, DVD, CD-ROM, flash memory, volatile or non-volatile memory, or any other suitable digital storage medium for storing encoded video data. , may include any of a variety of distributed or locally accessed data storage media.

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

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 include a web server (e.g., for a website), a file transfer protocol service (such as File Transfer Protocol (FTP) or File Delivery over Unidirectional Transport (FLUTE) protocol). a server, content delivery network (CDN) device, hypertext transfer protocol (HTTP) server, multimedia broadcast multicast service (MBMS) or enhanced MBMS (eMBMS) server configured to provide (NAS) device. File server 114 may additionally or alternatively support Dynamic Adaptive Streaming over HTTP (DASH), HTTP Live Streaming (HLS), Real Time Streaming Protocol (RTSP), HTTP One or more HTTP streaming protocols may be implemented, such as HTTP Dynamic Streaming.

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

Output interface 108 and input interface 122 may be a wireless transmitter/receiver, modem, wired networking component (e.g., an Ethernet card), wireless communication component operating in accordance with any of the various IEEE 802.11 standards, or other physical can represent a component. In examples where output interface 108 and input interface 122 comprise wireless components, output interface 108 and input interface 122 are encoded according to cellular communication standards such as 4G, 4G-LTE (Long Term Evolution), LTE Advanced, 5G, etc. The device may be configured to transfer data such as video data. In some examples where output interface 108 comprises a wireless transmitter, output interface 108 and input interface 122 may be compatible with other standards such as the IEEE 802.11 specification, the IEEE 802.15 specification (e.g., ZigBee(TM)), the Bluetooth(TM) standard, etc. may be configured to transfer data, such as encoded video data, in accordance with a wireless standard. In some examples, source device 102 and/or destination device 116 may include respective system-on-chip (SoC) devices. For example, source device 102 may include an SoC device for performing functions attributable to video encoder 200 and/or output interface 108, and destination device 116 may include a SoC device for performing functions attributable to video decoder 300 and/or input interface 122. May include an SoC device for execution.

The techniques of this disclosure can be applied to over-the-air television broadcasts, cable television transmissions, satellite television transmissions, Internet streaming video transmissions such as Dynamic Adaptive Streaming over HTTP (DASH), and digital video encoded on a data storage medium. It may be applied to video coding to support any of a variety of multimedia applications, such as decoding digital video stored on a data storage medium, or other applications.

Input interface 122 of destination device 116 receives an encoded video bitstream from computer-readable medium 110 (eg, a communication medium, storage device 112, file server 114, etc.). A coded video bitstream consists of video elements, such as syntax elements having values that describe the characteristics and/or processing of video blocks or other coded units (e.g., slices, pictures, picture groups, sequences, etc.). It may include signaling information defined by encoder 200 and also used by video decoder 300. Display device 118 displays decoded pictures of the decoded video data to the 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 each be integrated with an audio encoder and/or audio decoder, allowing audio and video in a common data stream. A suitable MUX-DEMUX unit, or other hardware and/or software, may be included to process multiplexed streams containing both. If applicable, the MUX-DEMUX unit may comply with the ITU H.223 multiplexer protocol or other protocols such as User Datagram Protocol (UDP).

Video encoder 200 and video decoder 300 each include one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), discrete logic, software, hardware, May be implemented as any of a variety of suitable encoder and/or decoder circuits, such as firmware or any combination thereof. When the techniques are partially implemented in software, the device stores instructions for the software on a suitable non-transitory computer-readable medium and uses one or more processors to execute the techniques of this disclosure. can execute instructions in hardware. Each of video encoder 200 and video decoder 300 may be included in one or more encoders or decoders, any of which may be integrated as part of a combined encoder/decoder (CODEC) in their respective devices. There is. Devices including video encoder 200 and/or video decoder 300 may include integrated circuits, microprocessors, and/or wireless communication devices such as cellular telephones.

Video encoder 200 and video decoder 300 may operate according to a video coding standard such as ITU-T H.265, also referred to as High Efficiency Video Coding (HEVC), or extensions thereof such as multi-view and/or scalable 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). The draft VVC standard is published by 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: via remote conference, from June 22 to July 1, 2020, as described in JVET-S2001-vA (hereinafter referred to as “VVC Draft 10”). However, the techniques of this disclosure are not limited to any particular coding standard.

Generally, 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, 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. Generally, 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 the chrominance component chrominance components of both the blue and blue hues. 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-processing units and post-processing units (not shown) may perform these conversions.

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

HEVC defines various blocks, including coding units (CUs), prediction units (PUs), and transform units (TUs). According to HEVC, a video coder (such as video encoder 200) partitions coding tree units (CTUs) into CUs according to a quadtree structure. That is, the video coder partitions the CTU and CU into four equal non-overlapping squares, where each node in the quadtree has either 0 or 4 child nodes. A node without child nodes may be referred to as a "leaf node," and the CU of such a leaf node may include one or more PUs and/or one or more TUs. A video coder may further partition PUs and TUs. For example, in HEVC, a residual quadrant tree (RQT) represents a partition of a TU. In HEVC, PU represents inter-predicted data and TU represents residual data. A CU that is intra-predicted includes intra-prediction information such as an intra-mode indication.

As another example, video encoder 200 and video decoder 300 may be configured to operate according to VVC. According to VVC, a video coder (such as video encoder 200) partitions a picture into multiple coding tree units (CTUs). Video encoder 200 may partition CTUs according to a tree structure, such as a quadrilateral tree (QTBT) structure or a multitype tree (MTT) structure. The QTBT structure eliminates the concept of multiple partition types, such as the distinction between HEVC's CU, PU, and TU. The QTBT structure includes two levels: a first level partitioned according to quadtree partitioning and a second level partitioned according to binary partitioning. The root node of the QTBT structure corresponds to the CTU. Leaf nodes of the binary tree correspond to coding units (CUs).

In the MTT partition structure, blocks are divided into quadtree (QT) partitions, binary tree (BT) partitions, and one or more types of ternary tree (TT) partitions. ) can be partitioned using partitions. A triple tree or ternary tree partition is a partition in which a block is divided into three subblocks. In some examples, a triple tree or ternary tree partition divides a block into three subblocks without splitting the original block through the center. The partition types in MTT (eg, QT, BT, and TT) can 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 decoder 300 can contain two or more QTBT/MTT structures, such as one QTBT/MTT structure for the luminance component and another QTBT/MTT structure for both chrominance components (or two QTBT/MTT structures for each chrominance component). QTBT or MTT structures may be used.

Video encoder 200 and video decoder 300 may be configured to use quadtree partitioning, QTBT partitioning, MTT partitioning, or other partitioning structures per HEVC. For purposes of explanation, the description of the techniques of this disclosure is presented with respect to the QTBT segment. 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 an array of three samples, or three used to code a monochrome picture or samples. Contains sample CTBs of pictures coded using two distinct color planes and syntax structures. A CTB can be an N×N block of samples for some value of N, such that the division of components into CTBs is piecewise. The components are arrays from or of one of three arrays (luma and two chromas) that create a picture in 4:2:0, 4:2:2, or 4:4:4 color format. A single sample or an array or a single sample of an array that creates a picture in monochrome format. In some examples, the coding block is an M×N block of samples for some value of M and N, such that the division of the CTB into coding blocks is partitioned.

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

In some examples, a tile may be partitioned into multiple bricks, and each brick may include one or more CTU rows within the tile. Tiles that are not divided into multiple bricks may also be called bricks. However, bricks that are a true subset of tiles may not be called tiles.

Bricks in a picture can also be ordered in slices. A slice may be an integer number of bricks of a picture that may be contained exclusively in a single network abstraction layer (NAL) unit. In some examples, a slice includes either a number of complete tiles or only a contiguous sequence of complete bricks of one tile.

This disclosure uses "N×N" and "N by N" interchangeably to refer to the sample dimension of a block (such as a CU or other video block) in terms of vertical and horizontal dimensions. ”, for example, 16×16 samples or 16 by 16 samples may be used. Generally, a 16x16 CU has 16 samples vertically (y=16) and 16 samples horizontally (x=16). Similarly, an N×N CU generally has N samples in the vertical direction and N samples in the horizontal direction, where N represents a non-negative integer value. Samples within a CU may be arranged in rows and columns. Furthermore, a CU does not necessarily need to have the same number of samples horizontally as vertically. For example, a CU may comprise 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, as well as other information. Prediction information indicates how a CU is to be predicted to form a prediction block for the CU. Residual information generally represents the sample-by-sample difference between the samples of the CU and the samples of the predictive block prior to encoding.

To predict a CU, video encoder 200 may generally form a prediction block for the CU through 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 motion searching, for example, to identify a reference block that closely matches a CU with respect to the difference between the CU and the reference block. Video encoder 200 uses sum of absolute differences (SAD), sum of squared differences (SSD), mean absolute difference (MAD), mean squared difference, etc. to determine whether a reference block exactly matches the current CU. (MSD), or other such difference calculations may be used to calculate the difference metric. In some examples, video encoder 200 may predict the current CU using unidirectional prediction or bidirectional prediction.

Some examples of VVC also provide an affine motion compensation mode, which can be considered an inter-prediction mode. In 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 predictive blocks. Some examples of VVC provide 67 intra-prediction modes, including various directional modes, as well as planar and DC modes. Generally, video encoder 200 selects an intra prediction mode that describes adjacent samples to a current block (eg, a block of a CU) from which to predict samples of the current block. Such samples generally include the top, top, and bottom of the current block in the same picture as the current block, assuming that video encoder 200 codes CTUs and CUs in raster scan order (left to right, top to bottom). It can be on the left side, or on the left side.

Video encoder 200 encodes data representing the prediction mode for the current block. For example, for inter-prediction modes, video encoder 200 may encode data representing which of the various available inter-prediction modes will be used, as well as motion information for the corresponding modes. For unidirectional or bidirectional inter-prediction, for example, video encoder 200 may encode motion vectors using advanced motion vector prediction (AMVP) or merge mode. Video encoder 200 may use a similar mode to encode motion vectors for affine motion compensation mode.

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 the sample-by-sample difference between a block and a predicted block for that block formed using a corresponding prediction mode. Video encoder 200 may apply one or more transforms to the residual block to generate transform data in the transform domain rather than 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. In addition, video encoder 200 may perform a mode-dependent non-separable secondary transform (MDNSST), a signal-dependent transform, and a Karhunen-Loeve transform (KLT) following the first transform. A quadratic transformation such as -Loeve transform) may be applied. Video encoder 200 generates transform coefficients following application of one or more transforms.

As described above, following any transformation 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 as much as possible the amount of data used to represent the transform coefficients, achieving further compression. By performing a 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 truncate 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 and 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 back of the vector. In some examples, video encoder 200 uses a predefined method for scanning the quantized transform coefficients to generate a serialized vector and then entropy encode the quantized transform coefficients of the vector. A different scan order can be used. In other examples, video encoder 200 may perform adaptive scanning. 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 in a context model to the symbols to be transmitted. The context may relate, for example, to whether neighboring values of the symbol are zeroed. The probability determination may be based on the context assigned to the symbol.

The video encoder 200 may, for example, encode a picture header, a block header, a slice header, or other syntax data such as a sequence parameter set (SPS), a picture parameter set (PPS), or a video parameter set (VPS) into a video decoder. Syntax data such as block-based syntax data, picture-based syntax data, and sequence-based syntax data may further be generated. Video decoder 300 may similarly decode such syntax data to determine how to decode the corresponding video data.

In this way, video encoder 200 generates encoded video data, e.g., a bitstream that includes syntax elements that describe the partitioning of pictures into blocks (e.g., CUs) and prediction and/or residual information about the blocks. can be generated. Ultimately, video decoder 300 may receive the bitstream and decode the encoded video data.

Generally, video decoder 300 performs a process that is the reverse of 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 that is opposite to, but substantially similar to, video encoder 200's CABAC encoding process. The syntax element may define partitioning information for partitioning pictures into CTUs and partitioning each CTU according to a corresponding partitioning structure, such as a QTBT structure, to define CUs of CTUs. The syntax elements may further define prediction and residual information for a block of video data (eg, a CU).

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

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

According to the techniques of this disclosure, as described in more detail below, video encoder 200 and video decoder 300 construct a total most probable mode list that includes N entries, the total most probable mode constructing and the first Np entries in the total most probable mode list, the N entries of the list are intra-prediction modes, and the planar mode is the first entry in the total most probable mode list. constructing a first-order most probable mode list from the remaining (N-Np) entries in the total most probable mode list, with Np less than N, and a second-order most probable mode from the remaining (N-Np) entries in the total most probable mode list determining a current intra-prediction mode for a current block of video data using a first-order most probable mode list or a second-order most likely mode list; and using the current intra-prediction mode. and decoding a current block of video data.

Exemplary intra-coding modes include DC mode, planar mode, and multiple directional modes (eg, non-planar mode). VVC, J. Chen, Y. Ye, and S.-H. Kim, “Algorithm description for Versatile Video Coding and Test Model 9 (VTM 9),” JVET-R2002, April 2020, describes the intra-prediction of blocks. 65 directional modes are used for this purpose. To code intra mode values, 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 only signal 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, the MPM list has 6 entries. The first entry in the MPM list is planar mode. The remaining entries in the MPM list are the intra modes of the left (L) and top (A) adjacent blocks of the CU400 (see Figure 2), the intra modes derived from the directional intra modes of the adjacent blocks, and the default Consists of intra mode. In the remainder of the discussion in this disclosure, this MPM list will be referred to as the primary MPM list.

A. Ramasubramonian et al., “CE3-3.1.1: Two MPM modes and shape dependency (Test 3.1.1),” Joint Video Exploration Team of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29/WG 11. (JVET), 11th Conference: Ljubljana, Slovenia, 10-18 July 2018 (hereinafter referred to as "JVET-K0081"), two MPM lists were proposed. One MPM list is a primary MPM (PMPM) list with 6 entries, and the other MPM list is a secondary MPM (SMPM) list with 16 entries. Entries in the PMPM list use the intra mode of the left (L), top (A), bottom left (BL), top right (AR), and top left (AL) adjacent blocks of the CU402, as shown in Figure 3. It is derived as follows. 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 in the PMPM list is intramode 12 and the maximum offset is 4, then intramodes 11, 10, 9, 8, 13, 14, 15, and 16 are each such intramode It will be added to the SMPM list provided it is not already included in two MPM lists. That is, all modes from intramode index 12 plus or minus 4 indices are added to the list unless such modes are duplicates of modes already in the list.

The maximum offsets used for the 6 primary MPMs in JVET-K0081 are {4, 3, 3, 2, 2, 1}. If the 16 entries in the SMPM list are not populated by this process, the remaining entries are populated from the intra mode default list. A video encoder may signal a syntax element that indicates whether a block's intra prediction mode is from a PMPM list or an 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 total most probable mode list and then constructing a first order most probable mode list and a second order most probable mode list from the total most probable mode list. The first most probable mode list and the second most probable mode list may include intra prediction modes from neighboring blocks as well as intra prediction modes offset from the intra prediction modes of neighboring blocks.

Total MPM list construction

Initially, a total 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 (eg, GMPM[0]) into the GMPM list indicates planar intra mode. For example, as shown in Figure 3, the intra modes of the left (L), top (A), bottom left (BL), top right (AR), and top left (AL) adjacent blocks of the currently coded block are, respectively. May be designated as MPM(L), MPM(A), MPM(BL), MPM(AR), and MPM(AL).

Video encoder 200 and video decoder 300 perform intra mode MPM(L), MPM(A), MPM(BL), MPM( AR), and MPM(AL) into 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, neighboring blocks may have associated intra prediction modes even if they are not coded using intra prediction.

Video encoder 200 and video decoder 300 detect the first Na available directionality among MPM(L), MPM(A), MPM(BL), MPM(AR), and MPM(AL) intra prediction modes. The remaining entries in the GMPM list can be derived by offsetting the intra mode, where Na is the left (L), top (A), bottom left (BL), top right (AR), and top left (AL) adjacent A number smaller than the number of blocks. For example, Na can be less than 5.

The intra mode of MPM(L), MPM(A), MPM(BL), MPM(AR), and MPM(AL) included in the GMPM list is indicated as GMPM[ p ]=MPM( j ). , 1≦p≦Nb, Nb is less than or equal to 5, and j is one of L, A, BL, AR, and AL. If p is less than the predefined value q, the maximum offset is set as M1, otherwise the maximum offset is set as M2. If N entries in the GMPM list are not populated by the proposed process, the remainder of the entries are populated from the default list. The first Np entries in the GMPM list are configured as the PMPM list, and the remaining (N-Np) entries in the GMPM list are configured as the SMPM list.

As an example, if the first entry in the PMPM list is intra mode 12 and the maximum offset is 4, then intra modes 11, 10, 9, 8, 13, 14, 15 and 16 are each such intra mode is added to the SMPM list provided that it is not already included in two MPM lists. That is, all modes from intramode index 12 plus or minus 4 indices are added to the list unless such modes are duplicates of modes already in the list. In another example, if the first entry in the PMPM list is intra mode 12 and the maximum offset is 3, then intra modes 11, 10, 9, 13, 14, and 15 are each such intra mode It will be added to the SMPM list provided it is not already included in two MPM lists. That is, all modes with intramode index 12 plus or minus 3 indices are added to the list, provided that such modes are not 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, with the first 6 entries being the PMPM list and the last 16 entries being the SMPM list. The first two available directional intra modes in MPM(L), MPM(A), MPM(BL), MPM(AR), and MPM(AL) are directional intramodes are offset to derive the directional intramodes near the directional intramodes. In this context, near means plus M1 or M2 indices or minus M1 or M2 indices from the available directional intra mode indices. When GMPM[ 1 ] and GMPM[ 2 ] are in non-DC mode, the maximum offset is 4 for GMPM[ 1 ] and GMPM[ 2 ]. If GMPM[ 1 ] is in DC mode and GMPM[ 2 ] and GMPM[ 3 ] are in non-DC mode, the maximum offset is 4 for GMPM[ 2 ] and 3 for GMPM[ 3 ]. be. If GMPM[ 2 ] is in DC mode and GMPM[ 1 ] and GMPM[ 3 ] are in non-DC mode, the maximum offset is 4 for GMPM[ 1 ] and 3 for GMPM[ 3 ]. be. For example, if GMPM[ 1 ]=20 and GMPM[ 3 ]=40, modes 16, 17, 18, 19, 21, 22, 23, and 24 offset from GMPM[ 1 ], and GMPM[ Modes 37, 38, 39, 41, 42, and 43 offset from [3] are added in 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 CU's intra mode is the first entry in the PMPM list. If the plane flag does not indicate a plane mode, video decoder 300 is configured to decode and parse an index value (e.g., a syntax element indicating an index value) to determine which entry in the PMPM list is selected. may be configured. The parsed index values 0, 1, 2, 3, and 4 correspond to the 1st entry, 2nd entry, 3rd entry, 4th entry, 5th entry of the PMPM list, respectively, Note that the parsed bins for index values 0, 1, 2, 3, and 4 are 0, 10, 110, 1110, 1111, respectively.

New coding tools called Intra Sub-Partition (ISP) and Multiple Reference Line (MRL) modes have been incorporated into VVC. ISP mode and normal intra mode share the same PMPM list. The MRL modes apply to the first entry, i.e., the intra modes in the PMPM list, except for the planar mode. Normal intra mode, ISP mode, and MRL mode all share the same non-planar PMPM entries, i.e. 1st entry, 2nd entry, 3rd entry, 4th entry, 5th entry in the PMPM list Therefore, context coding conditional on a selected mode among the normal intra mode, ISP mode, and MRL mode will improve the coding efficiency when signaling the PMPM index. Therefore, 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 the non-planar PMPM index as follows: .
(ISP mode): Code the first bin of the non-planar PMPM index using context index 0.
Otherwise (MRL mode): Use context index 1 to code the first bin of the non-planar PMPM index.
Otherwise (normal intra mode): Code the first bin of the non-planar PMPM index using context index 2.

When using the techniques of this disclosure, the if-else order can be changed to other combinations. An example is below.
(MRL mode): Code the first bin of the non-planar PMPM index using context index 0.
Otherwise (ISP mode): Use context index 1 to code the first bin of the non-planar PMPM index.
Otherwise (normal intra mode): Code the first bin of the non-planar PMPM index using context index 2.

(Example)
As explained above, two MPM lists may be used. That is, 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 total MPM list with 22 entries, and the first six entries in this total MPM list are in the PMPM list. The rest of the 22 entries are set to be the SMPM list. The first entry (eg, ordinal first entry) in the total MPM list is the planar mode. The remaining entries are the intra modes of the left (L), top (A), bottom left (BL), top right (AR), and top left (AL) adjacent blocks and the first two of the adjacent blocks, as shown in Figure 3. consists of a directional mode offset from the available directional modes, and a default mode. If the CU block is rectangular and oriented vertically, i.e. when the height is greater than the width, the order of neighboring blocks checked for available intra prediction modes is A, L, BL, AR, AL It is. Otherwise, the order is L, A, BL, AR, AL.

The maximum offset for a directional mode of a neighboring block depends on the entry point of this directional mode in the total MPM list. If the available directional mode of the neighboring block is either the second entry or the third entry (note that the first entry is the planar mode), the maximum offset is set as 4, Otherwise, the maximum offset is set as 3. For example, the ith entry in the total MPM list is denoted as GMPM[i]. GMPM[ 0 ]=Planar mode. When GMPM[ 1 ] is in DC mode and GMPM[ 2 ] and GMPM[ 3 ] are in directional mode, the maximum offset is 4 for GMPM[ 2 ] and 3 for GMPM[ 3 ]. be. Assume that GMPM[ 2 ]=20 and GMPM[ 3 ]=40. In that case, 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 ] Added to GMPM list.

Video decoder 300 may first decode and parse the plane flag to determine whether the CU's intra mode is the first entry in the PMPM list. If the planar flag does not indicate that planar mode should be used, video decoder 300 decodes the index value of the non-planar mode in the PMPM list to determine which entry in the PMPM list is selected. and parse. The parsed index values 0, 1, 2, 3, 4 in non-planar mode correspond to the 1st entry, 2nd entry, 3rd entry, 4th entry, 5th entry in the PMPM list. , note that the parsed bins for index values 0, 1, 2, 3, 4 are 0, 10, 110, 1110, 1111, respectively. Video encoder 200 and video decoder 300 may be configured to use three context models to code the first bin of non-planar mode indices in the PMPM list as follows.
(ISP): Code the first bin using context index 0.
Otherwise, if (MRL): Code the first bin using context index 1.
Otherwise (usually intra): Code the first bin using 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. The video decoder 300 constructs a total most probable mode list including N entries, where N entries of the total most probable mode list are intra prediction modes and planar modes are of the total most probable mode list. may be configured to do the following: The video decoder 300 is configured to construct a first order most probable mode list from the first Np entries in the total most probable mode list, where Np is less than N; and constructing a quadratic most probable mode list from the remaining (N-Np) entries in the list. Video decoder 300 then determines the current intra-prediction mode for the current block of video data using the first-order most probable mode list or the second-order most probable mode list and the decoded block of video data. The current block of video data may be decoded using the current intra-prediction mode to generate the current intra-prediction mode. In one example, N is 22 and Np is 6.

In one example, to determine the current intra-prediction mode, video decoder 300 decodes an index into a first-order most probable mode list or a second-order most probable mode list, where the index The method may be further configured to indicate and decode a non-planar intra-prediction mode in the mode list or the quadratic most probable mode 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 first-order most probable mode list or a second-order most probable mode list, video decoder 300 determines the first bin of the index based on the coding tool used for the current block. The method may further include determining a context for entropy decoding and using the context to entropy decode the first bin of the index. In one example, the coding tool is in one of a normal intra prediction mode, an intra subpartition mode, or a multiple reference line mode.

In another example of the present disclosure, to construct the total most probable mode list, video decoder 300 adds each intra-prediction mode from each neighboring block of the current block of video data to the total most probable mode list. and adding a plurality of intra prediction modes offset from respective intra prediction modes from respective neighboring blocks to the total most probable mode list. In one example, video decoder 300 determines whether the respective intra prediction modes from respective neighboring blocks of the current block of video data are available based on whether the respective intra prediction modes are available and have not yet been added to the total most probable mode list. Predictive modes may be added to the total most probable mode list.

In other examples, to determine the current intra-prediction mode for the current block of video data using a first-order most probable mode list or a second-order most probable mode list, video decoder 300 uses a first-order most likely decoding a syntax element indicating a current most probable mode list from either a mode list or a quadratic most probable mode list; decoding an index into the current most probable mode list; and determining a current intra-prediction mode from the index into the mode list.

In a converse manner, video encoder 200 is also configured to encode the current block of video data using intra prediction. The video encoder 200 constructs a total most probable mode list including N entries, where the N entries of the total most probable mode list are intra prediction modes, and the planar modes are of the total most probable mode list. may be configured to do the following: Video encoder 200 is configured to construct a first order most probable mode list from the first Np entries in the total most probable mode list, where Np is less than N; and constructing a quadratic most probable mode list from the remaining (N-Np) entries in the list. Video encoder 200 determines a current intra-prediction mode for a current block of video data using a first-order most probable mode list or a second-order most probable mode list and an encoded block of video data. The method may further include encoding the current block of video data using the current intra prediction mode to generate the video data. In one example, N is 22 and Np is 6.

In one example of the present disclosure, video encoder 200 encodes an index to a first-order most probable mode list or a second-order most probable mode list, the index being a first-order most probable mode list or a second-order most probable mode list. The method may be configured to perform encoding indicating a non-planar intra prediction mode in the mode list.

In another example of the present disclosure, to encode an index to a first-order most probable mode list or a second-order most probable mode list, video encoder 200 may determine the index of the index based on the coding tool currently used for the block. The method may be configured to determine a context for entropy encoding a first bin and entropy encoding a first bin of the index using the context. In one example, the coding tool is in one of a normal intra prediction mode, an intra subpartition mode, or a multiple reference line mode.

In another example, to construct the total most probable mode list, video encoder 200 adds each intra-predicted mode from each neighboring block of the current block of video data to the total most probable mode list; and adding a plurality of intra prediction modes offset from respective intra prediction modes from respective neighboring blocks to the total most probable mode list. Video encoder 200 selects each intra-prediction mode from each adjacent block of the current block of video data based on whether the respective intra-prediction mode is available and has not yet been added to the total most probable mode list. Can be added to the total most probable mode list.

4A and 4B are conceptual diagrams illustrating an example quadtree binary tree (QTBT) structure 130 and a corresponding coding tree unit (CTU) 132. Solid lines represent quadtree partitioning, and dotted lines represent binary tree partitioning. At each split (i.e., non-leaf) node of the binary tree, one flag is signaled to indicate which split type (i.e., horizontal or vertical) is used, where, in this example, 0 Indicates horizontal division and 1 indicates vertical division. For quadtree partitioning, there is no need to indicate the partition type because the quadtree node partitions the block horizontally and vertically into four equal-sized subblocks. Therefore, video encoder 200 uses syntax elements (such as segmentation information) for the region tree level (i.e., solid lines) of QTBT structure 130 and (segmentation information) for the prediction tree level (i.e., dashed lines) of QTBT structure 130. ), and video decoder 300 may decode those syntax elements. Video encoder 200 may encode video data, such as prediction data and transform data, for a CU represented by a terminal leaf node of QTBT structure 130, and video decoder 300 may decode the video data.

In general, CTU 132 of FIG. 4B may be associated with parameters that define the size of blocks corresponding to nodes of QTBT structure 130 at a first level and a second level. These parameters are CTU size (representing the size of CTU132 in the sample), minimum quadtree size (MinQTSize, representing the smallest allowed quadtree leaf node size), maximum binary tree size (MaxBTSize, representing the maximum ), the maximum binary tree depth (MaxBTDepth, which represents the maximum allowed binary tree root node size), and the minimum binary tree size (MinBTSize, which represents the minimum allowed binary tree depth of 2 (representing the branch tree leaf node size).

The root node of the QTBT structure corresponding to a CTU may have four child nodes at the first level of the QTBT structure, and each of the child nodes may be partitioned according to the quadtree partition. That is, a first level node is either a leaf node (with no child nodes) or has four child nodes. An example QTBT structure 130 represents a node that includes a parent node and a child node with solid lines for branching. If the first level nodes are not larger than the maximum allowed binary tree root node size (MaxBTSize), these nodes may be further partitioned by the respective binary tree. Binary tree splitting of one node may be repeated until the resulting node of the split reaches the minimum allowed binary tree leaf node size (MinBTSize) or the maximum allowed binary tree depth (MaxBTDepth) . The example QTBT structure 130 represents such nodes with dashed lines for branches. Binary tree leaf nodes are called coding units (CUs), and coding units (CUs) are used for prediction (eg, intra-picture prediction or inter-picture prediction) and transformation without further partitioning. As explained above, a CU is sometimes referred to as a "video block" or "block."

In an example QTBT partitioned structure, CTU size is set as 128x128 (luma sample and two corresponding 64x64 chroma samples), MinQTSize is set as 16x16, MaxBTSize is set as 64x64, and ( MinBTSize (for both width and height) is set as 4 and MaxBTDepth is set as 4. To generate quadtree leaf nodes, quadtree partitioning is first applied to the CTU. A quadtree leaf node may have a size from 16×16 (ie, MinQTSize) to 128×128 (ie, CTU size). If a quadtree leaf node is 128x128, the leaf quadtree node is not further divided by the binary tree because the size exceeds MaxBTSize (ie, 64x64 in this example). Otherwise, the quadtree leaf nodes are further partitioned by a binary tree. Therefore, the quadtree leaf node is also the root node of the binary tree and has the binary tree depth as 0. When the binary tree depth reaches MaxBTDepth (4 in this example), no further splits are allowed. A binary tree node with a width equal to MinBTSize (4 in this example) suggests that no further vertical splits (ie, width splits) are allowed for that binary tree node. Similarly, a binary tree node with a height equal to MinBTSize suggests that no further horizontal splits (ie, height splits) are allowed for that binary tree node. As mentioned above, the leaf nodes of the binary tree are called CUs and are further processed according to predictions and transformations without further partitioning.

FIG. 5 is a block diagram illustrating an example video encoder 200 that may implement the techniques of this disclosure. FIG. 5 is provided for illustrative purposes and should not be considered a limitation of the techniques as broadly illustrated and described in this disclosure. For purposes of illustration, this disclosure describes a video encoder 200 in accordance with VVC (ITU-T H.266 under development) and HEVC (ITU-T H.265) techniques. However, the techniques of this disclosure may be performed by video encoding devices configured according to other video coding standards.

In the example of FIG. 5, video encoder 200 includes 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, It includes a configuration unit 214, a filter unit 216, a decoded picture buffer (DPB) 218, and an 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 unit 214, filter unit 216, DPB 218, and Any or all of entropy encoding units 220 may be implemented in one or more processors or in processing circuitry. For example, a unit of video encoder 200 may be implemented as one or more circuits or logic elements as part of a hardware circuit, or as part of a processor, ASIC, or FPGA. Additionally, video encoder 200 may include additional or alternative processors or processing circuits to perform these and other functions.

Video data memory 230 may store video data to be encoded by components of video encoder 200. Video encoder 200 may receive video data stored in video data memory 230, for example, from video source 104 (FIG. 1). DPB 218 may act as a reference picture memory that stores reference video data for use in predicting subsequent video data by video encoder 200. Video data memory 230 and DPB 218 may be used in a variety of 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 can be formed by any of the following. 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 other components of video encoder 200, as shown, or off-chip with respect to those components.

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

The various units in FIG. 5 are illustrated to aid in understanding the operations performed by video encoder 200. A unit may be implemented as a fixed function circuit, a programmable circuit, or a combination thereof. Fixed function circuitry refers to circuitry that provides a specific function and is preset for the operations that may be performed. Programmable circuit refers to a circuit that can be programmed to perform a variety of tasks, providing flexibility in the operations that can be performed. For example, a programmable circuit may execute software or firmware that causes the programmable circuit to operate in a manner defined by the software or firmware instructions. Although fixed function circuits may execute software instructions (eg, to receive parameters or output parameters), the types of operations that fixed function circuits perform generally remain unchanged. In some examples, one or more of the units may be different circuit blocks (fixed function or programmable), and in some examples, one or more of the units may be an integrated circuit. Good too.

Video encoder 200 may include a programmable core formed from an arithmetic logic unit (ALU), an elementary function unit (EFU), digital circuitry, analog circuitry, and/or programmable circuitry. In examples where the operations of video encoder 200 are performed using software executed by programmable circuitry, memory 106 (FIG. 1) stores software instructions (e.g., object code) that video encoder 200 receives and executes. or another memory (not shown) within video encoder 200 may store such instructions.

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

Mode selection unit 202 includes a motion estimation unit 222, a motion compensation unit 224, and an intra prediction unit 226. Mode selection unit 202 may include additional functional units for performing video prediction according to other prediction modes. By way of example, mode selection unit 202 may include 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.

Mode selection unit 202 generally coordinates multiple encoding passes to test combinations of encoding parameters and resulting rate-distortion values for such combinations. The encoding parameters may include partitioning of the CTU into CUs, a prediction mode for the CU, a transform type for the residual data of the CU, a quantization parameter for the residual data of the CU, etc. Mode selection unit 202 may ultimately select a combination of encoding parameters that has a better rate-distortion value 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 selection unit 202 may partition the CTU of a picture according to a tree structure, such as the HEVC QTBT structure or quadtree structure described above. As explained above, video encoder 200 may form one or more CUs from partitioning the CTUs according to a tree structure. Such a CU is also commonly referred to as a "video block" or "block."

In general, mode selection unit 202 also selects its components (e.g., motion estimation unit 222, a motion compensation unit 224, and an intra prediction unit 226). For inter prediction of the current block, motion estimation unit 222 determines whether one or more precisely Motion search may be performed to identify matching reference blocks. Specifically, motion estimation unit 222 estimates potential reference blocks according to, e.g., sum of absolute differences (SAD), sum of squared differences (SSD), mean absolute difference (MAD), mean squared difference (MSD), etc. may calculate a value representing how similar is the current block. Motion estimation unit 222 may generally perform these calculations using sample-by-sample differences between the current block and the considered reference block. Motion estimation unit 222 may identify the reference block with the lowest value resulting from these calculations, indicating the reference block that most closely matches the current block.

Motion estimation unit 222 may form one or more motion vectors (MVs) that define the position of a reference block in a reference picture relative to the position of a current block in a current picture. Motion estimation unit 222 may then provide the motion vector 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. Motion compensation unit 224 may then generate a predictive block using the motion vector. For example, motion compensation unit 224 may use motion vectors to retrieve data for reference blocks. As another example, if the motion vector has fractional sample accuracy, motion compensation unit 224 may interpolate the values for the predictive block according to one or more interpolation filters. Additionally, for bidirectional inter-prediction, motion compensation unit 224 retrieves the data for the two reference blocks identified by their respective motion vectors, e.g., by sample-by-sample averaging or weighted averaging. data can be synthesized.

As another example, for intra prediction or intra predictive coding, intra prediction unit 226 may generate a predictive block from samples adjacent to the current block. For example, for directional mode, intra prediction unit 226 typically mathematically combines the values of adjacent samples and populates these calculated values in a defined direction across the current block to generate the predicted block. obtain. As another example, for DC mode, intra prediction unit 226 may calculate the average of adjacent samples for the current block and generate a prediction block that should include this resulting average for each sample of the prediction block.

According to the techniques of the present disclosure described above, intra prediction unit 226 constructs a total most probable mode list including N entries, wherein the N entries of the total most probable mode list are intra predictions. mode and the planar mode is the first entry in the total most probable mode list, and constructing a first order most probable mode list from the first Np entries in the total most probable mode list. constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list, with Np less than N; Determining the current intra-prediction mode for the current block of video data using the most probable mode list or the quadratic most probable mode list and using the current and encoding a current block of video data using an intra-prediction mode.

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

In examples where mode selection unit 202 partitions CUs into PUs, each PU may be associated with a luma prediction unit and a corresponding chroma prediction unit. Video encoder 200 and video decoder 300 may support PUs with various sizes. As indicated above, the size of a CU may refer to the size of the luma coding block of the CU, and the size of the PU may refer to the size of the luma prediction unit of the PU. Assuming that the size of a particular CU is 2N×2N, video encoder 200 uses a PU size of 2N×2N or N×N for intra prediction and 2N×2N, 2N×N, Symmetrical PU sizes may be supported, such as N×2N, N×N, or similar. Video encoder 200 and video decoder 300 may also support asymmetric partitioning for PU sizes of 2N×nU, 2N×nD, nL×2N, and nR×2N for inter prediction.

In examples where mode selection unit 202 does not further partition the CUs into PUs, each PU may be associated with a luma coding block and a corresponding chroma coding block. As mentioned above, the size of a CU may refer to the size of the luma coding block of the CU. Video encoder 200 and video decoder 300 may support CU sizes of 2N×2N, 2N×N, or N×2N.

For other video coding techniques, such as intra block copy mode coding, affine mode coding, and linear model (LM) mode coding, as some examples, mode selection unit 202 selects the respective units associated with the coding technique. generate a predictive block for the current block being encoded. In some examples, such as palette mode coding, mode selection unit 202 may not generate predictive blocks, but instead generates syntax elements that indicate how to reconstruct the blocks based on the selected palette. You may. In such a mode, mode selection unit 202 may provide these syntax elements to be encoded to entropy encoding unit 220.

As explained above, residual generation unit 204 receives video data for the current block and the 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 the sample-by-sample difference between the predicted block and the current block.

Transform processing unit 206 applies one or more transforms to the residual block to generate a block of transform coefficients (referred to herein as a "transform coefficient block"). 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, eg, linear and quadratic transforms, such as rotation transforms, on the residual block. In some examples, transform processing unit 206 does not apply a transform 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 the transform coefficient block according to a quantization parameter (QP) value associated with the current block. Video encoder 200 (e.g., via mode selection unit 202) may adjust the degree of quantization applied to the transform coefficient block associated with the current block by adjusting the QP value associated with the CU. . Quantization may result in a loss of information, and therefore the quantized transform coefficients may have lower accuracy than the original transform coefficients produced by transform processing unit 206.

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

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

Video encoder 200 stores the reconstructed blocks in DPB 218. For example, in instances where the operations of filter unit 216 are not performed, reconstruction unit 214 may store reconstructed blocks in DPB 218. In examples where the operations of filter unit 216 are performed, filter unit 216 may store the filtered and reconstructed blocks in DPB 218. Motion estimation unit 222 and motion compensation unit 224 extract reference pictures formed from the reconstructed (and possibly filtered) blocks from DPB 218 in order to inter-predict blocks of pictures that are subsequently coded. It can be taken out. Additionally, intra prediction unit 226 may use the reconstructed blocks in DPB 218 of the current picture to intra predict other blocks in the current picture.

Generally, 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 block from quantization unit 208. As another example, entropy encoding unit 220 may entropy encode prediction syntax elements (eg, motion information for inter prediction or intra mode information for intra prediction) from mode selection unit 202. Entropy encoding unit 220 may perform one or more entropy encoding operations on syntax elements that are 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 A piecewise entropy (PIPE) coding operation, an exponential Golomb coding operation, or another type of entropy coding operation 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 needed to reconstruct slices or blocks of pictures. Specifically, entropy encoding unit 220 may output a bitstream.

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

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

Video encoder 200 is a device configured to encode video data, comprising a memory configured to store the video data and a total most probable mode list implemented in circuit and including N entries. , the N entries of the total most probable mode list are intra-prediction modes, and the planar mode is the first entry in the total most probable mode list. constructing a first-order most probable mode list from the first Np entries in the probable mode list, where Np is less than N, and the remaining (N -Np) entries and use the first-order most probable mode list or the second-order most probable mode list to determine the current intra-prediction mode for the current block of video data. one or more configured to: determine, and encode the current block of video data using the current intra prediction mode to generate an encoded block of video data. represents an example of a device including a processing unit.

FIG. 6 is a block diagram illustrating an example video decoder 300 that may implement the techniques of this disclosure. FIG. 6 is provided for purposes of illustration and not limitation of the techniques as broadly illustrated and described in this disclosure. For purposes of explanation, this disclosure describes a video decoder 300 in accordance with VVC (ITU-T H.266 under development) and HEVC (ITU-T H.265) techniques. However, the techniques of this disclosure may be performed by video coding devices configured according to other video coding standards.

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

Prediction processing unit 304 includes a motion compensation unit 316 and an intra prediction unit 318. Prediction processing unit 304 may include additional units for performing predictions according to other prediction modes. By way of example, 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, etc. 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 components of video decoder 300. Video data stored in CPB memory 320 may be obtained from computer-readable medium 110 (FIG. 1), for example. 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 coded picture syntax elements, such as temporal data representing output 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 subsequent data or pictures of the 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. CPU 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 other components of video decoder 300 or off-chip with respect to those components.

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 described above with respect to CPB memory 320. Similarly, 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 to be executed by processing circuitry of video decoder 300.

The various units shown in FIG. 6 are illustrated to aid in understanding the operations performed by video decoder 300. A unit may be implemented as a fixed function circuit, a programmable circuit, or a combination thereof. Similar to FIG. 5, fixed function circuits refer to circuits that provide a specific function and are preset for operations that may be performed. Programmable circuit refers to a circuit that can be programmed to perform a variety of tasks, providing flexibility in the operations that can be performed. For example, a programmable circuit may execute software or firmware that causes the programmable circuit to operate in a manner defined by the software or firmware instructions. Although fixed function circuits may execute software instructions (eg, to receive parameters or output parameters), the types of operations that fixed function circuits perform generally remain unchanged. In some examples, one or more of the units may be different circuit blocks (fixed function or programmable), and in some examples, one or more of the units may be an integrated circuit. Good too.

Video decoder 300 may include a programmable core formed from ALUs, EFUs, digital circuits, analog circuits, and/or programmable circuits. In examples where the operations of video decoder 300 are performed by software running on programmable circuitry, on-chip or off-chip memory stores software instructions (e.g., object code) that video decoder 300 receives and executes. obtain.

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

Generally, video decoder 300 reconstructs pictures block by block. Video decoder 300 may perform a reconstruction operation on each block individually (where the block currently being reconstructed, or decoded, may be referred to as a "current block").

Entropy decoding unit 302 may entropy decode the quantized transform coefficients of the quantized transform coefficient block as well as syntax elements that define transform information such as quantization parameters (QPs) and/or transform mode indications. Dequantization unit 306 determines the degree of quantization and, similarly, the QP associated with the quantized transform coefficient block to determine the degree of dequantization that dequantization unit 306 should apply. Can be used. Dequantization unit 306 may, for example, perform a bitwise left shift operation to dequantize 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 the transform coefficient block, inverse transform processing unit 308 applies one or more inverse transforms to the transform coefficient block to generate a residual block associated with the current block. obtain. For example, inverse transform processing unit 308 may apply an inverse DCT, an inverse integer transform, an inverse Karhunen-Loeve transform (KLT), an inverse rotation transform, an inverse transform, or another inverse transform to the block of transform coefficients.

Further, the prediction processing unit 304 generates a prediction block according to the prediction information syntax elements entropy decoded by the entropy decoding unit 302. For example, motion compensation unit 316 may generate a predictive block if the prediction information syntax element indicates that the current block is inter-predicted. In this case, the prediction information syntax element may indicate the reference picture in the DPB 314 from which the reference block is to be retrieved, as well as 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. . 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 prediction block according to the intra prediction mode indicated by the prediction information syntax element. Again, intra prediction unit 318 may generally perform an intra prediction process in a manner substantially similar to that described with respect to intra prediction unit 226 (FIG. 5). Intra prediction unit 318 may retrieve data for adjacent samples for the current block from DPB 314 .

According to the techniques described above, intra prediction unit 318 constructs a total most probable mode list including N entries, the N entries of the total most probable mode list being intra prediction modes. , where the planar mode is the first entry in the total most probable mode list, and by constructing a first-order most probable mode list from the first Np entries in the total most probable mode list. and Np is less than N, constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list, and Determining the current intra-prediction mode for the current block of video data using the list or quadratic most probable mode list and selecting the current intra-prediction mode to generate the decoded block of video data. decoding the current block of video data using the video data.

Reconstruction unit 310 may reconstruct the current block using the predictive block and the residual block. For example, reconstruction unit 310 may add samples of the residual 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 a deblocking operation to reduce blockiness artifacts along the edges of the reconstructed block. The operations of filter unit 312 are not necessarily performed in all instances.

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

In this way, video decoder 300 is implemented in circuitry and a memory configured to store video data, the total most probable mode list comprising N entries, the total most probable mode constructing and the first Np entries in the total most probable mode list, where the N entries of the list are intra-prediction modes and the planar mode is the first entry in the total most probable mode list constructing a first-order most probable mode list from the remaining (N-Np) entries in the total most probable mode list, with Np less than N; determining a current intra-prediction mode for a current block of video data using a first-order most probable mode list or a second-order most probable mode list; and determining a current intra-prediction mode for a current block of video data; Represents an example of a video decoding device that includes one or more processing units configured to: decode a current block of video data using a current intra prediction mode to generate a current block of video data.

FIG. 7 is a flowchart illustrating an example method for encoding a current block in accordance with the techniques of this disclosure. The current block may contain the 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.

In this example, video encoder 200 first predicts the current block (350). For example, video encoder 200 may form a predictive block for a 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). Video encoder 200 may then scan the quantized transform coefficients of the residual block (356). During or following scanning, video encoder 200 may entropy encode the transform coefficients (358). For example, video encoder 200 may encode transform coefficients using CAVLC or CABAC. Video encoder 200 may then output the block of entropy encoded data (360).

FIG. 8 is a flowchart illustrating an example method for decoding a current block of video data in accordance with the techniques of this disclosure. The current block may contain the 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.

Video decoder 300 may receive entropy encoded data for the current block, such as entropy encoded prediction information and entropy encoded data of 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 to recover transform coefficients for the residual block (372). Video decoder 300 may predict the current block using, for example, an intra-prediction mode or an inter-prediction mode as indicated by the prediction information for the current block to calculate a prediction block for the current block. (374). Video decoder 300 may then backscan the reconstructed transform coefficients to create 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 finally decode the current block by combining the predictive block and the residual block (380).

FIG. 9 is a flowchart illustrating another example method for encoding a current block in accordance with 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.

In one example of this disclosure, video encoder 200 is configured to encode a current block of video data using intra prediction. The video encoder 200 constructs a total most probable mode list including N entries, where the N entries of the total most probable mode list are intra prediction modes, and the planar modes are of the total most probable mode list. may be configured to perform constructing (500), which is the first entry in . Video encoder 200 comprises constructing (502) a first order most probable mode list from the first Np entries in the total most probable mode list, Np being less than N; The method may further include constructing (504) a quadratic most probable mode list from the remaining (N-Np) entries in the most probable mode list. Video encoder 200 determines (506) a current intra-prediction mode for a current block of video data using a first-order most probable mode list or a second-order most likely mode list; The method may further include encoding (508) the current block of video data using the current intra prediction mode to generate the predicted block. In one example, N is 22 and Np is 6.

In one example of the present disclosure, video encoder 200 encodes an index to a first-order most probable mode list or a second-order most probable mode list, the index being a first-order most probable mode list or a second-order most probable mode list. The method may be configured to perform encoding indicating a non-planar intra prediction mode in the mode list.

In another example of the present disclosure, to encode an index to a first-order most probable mode list or a second-order most probable mode list, video encoder 200 encodes the index based on the coding tool currently used for the block. The method may be configured to determine a context for entropy encoding a first bin and entropy encoding a first bin of the index using the context. In one example, the coding tool is in one of a normal intra prediction mode, an intra subpartition mode, or a multiple reference line mode.

In another example, to construct the total most probable mode list, video encoder 200 adds each intra-predicted mode from each neighboring block of the current block of video data to the total most probable mode list; and adding a plurality of intra prediction modes offset from respective intra prediction modes from respective neighboring blocks to the total most probable mode list. Video encoder 200 selects each intra-prediction mode from each neighboring block of the current block of video data based on whether the respective intra-prediction mode is available and has not yet been added to the total most probable mode list. Can be added to the total most probable mode list.

FIG. 10 is a flowchart illustrating another example method for decoding a current block in accordance with 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.

In one example of this disclosure, video decoder 300 may be configured to decode a current block of video data using intra prediction. The video decoder 300 constructs a total most probable mode list including N entries, wherein N entries of the total most probable mode list are intra prediction modes and planar modes are of the total most probable mode list. may be configured to perform constructing (600). Video decoder 300 comprises constructing (602) a first order most probable mode list from the first Np entries in the total most probable mode list, Np being less than N; The method may further include constructing (604) a quadratic most probable mode list from the remaining (N-Np) entries in the most probable mode list. Video decoder 300 then determines a current intra prediction mode for the current block of video data using the first order most probable mode list or the second order most probable mode list (606) and decodes the video data. The current block of video data may be decoded (608) using the current intra prediction mode to generate a predicted block. In one example, N is 22 and Np is 6.

In one example, to determine the current intra-prediction mode, video decoder 300 decodes an index into a first-order most probable mode list or a second-order most probable mode list, where the index The method may be further configured to indicate and decode a non-planar intra-prediction mode in the mode list or the quadratic most probable mode 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 first-order most probable mode list or a second-order most probable mode list, video decoder 300 determines the first bin of the index based on the coding tool used for the current block. The method may further include determining a context for entropy decoding and using the context to entropy decode the first bin of the index. In one example, the coding tool is in one of a normal intra prediction mode, an intra subpartition mode, or a multiple reference line mode.

In another example of the present disclosure, to construct the total most probable mode list, video decoder 300 adds each intra-prediction mode from each neighboring block of the current block of video data to the total most probable mode list. and adding a plurality of intra prediction modes offset from respective intra prediction modes from respective neighboring blocks to the total most probable mode list. In one example, video decoder 300 determines whether the respective intra prediction modes from respective neighboring blocks of the current block of video data are available based on whether the respective intra prediction modes are available and have not yet been added to the total most probable mode list. Predictive modes may be added to the total most probable mode list.

In other examples, to determine the current intra-prediction mode for the current block of video data using a first-order most probable mode list or a second-order most probable mode list, video decoder 300 uses a first-order most likely decoding a syntax element indicating a current most probable mode list from either a mode list or a quadratic most probable mode list; decoding an index into the current most probable mode list; and determining a current intra-prediction mode from the index into the mode list.

Additional aspects of the disclosure are described below.

Aspect 1A - A method of coding video data, the step of constructing a total most probable mode list comprising N entries, the N entries of the total most probable mode list being intra prediction modes. and the step of constructing a first-order most probable mode list from the first Np entries in the total most probable mode list, where Np is less than N; and the remaining in the total most probable mode list. constructing a second-order most probable mode list from (N-Np) entries; and determining an intra-prediction mode for the current block of video data using the first-order most probable mode list or the second-order most probable mode list. and determining the method.

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

Aspect 3A - The step of constructing the total most probable mode list comprises adding a planar mode as a first entry in the total most probable mode list and adding each intra from each neighboring block of the current block of video data. Aspects 1A and 2A, comprising adding a prediction mode to a total most probable mode list; and adding an intra prediction mode offset from each intra prediction mode from each neighboring block to a total most probable mode list. Either way.

Aspect 4A - Adding each intra prediction mode from each neighboring block of the current block of video data to the total most probable mode list includes the step of adding each intra prediction mode from each adjacent block of the current block of video data to the total most probable mode list if each intra prediction mode is available and not yet added to the total most probable mode list. The method of aspect 3A, comprising adding each intra prediction mode from each neighboring block of the current block of video data to the total most probable mode list, if not added.

Aspect 5A - The method of any of Aspects 1A-4A, further comprising determining a context for coding an index indicating a non-planar mode of the first-order most probable mode list based on a coding tool currently used for the block. Method.

Aspect 6A - The method of Aspect 5A, wherein the coding tool is in one of a normal intra prediction mode, an intra subpartition mode, or a multiple reference line mode.

Aspect 7A - The method of any of Aspects 1A-6A, wherein the step of encoding comprises the step of decoding.

Aspect 8A - The method of any of Aspects 1A-7A, wherein the step of coding comprises the step of encoding.

Aspect 9A - A device for coding video data, comprising one or more means for performing the method of any of Aspects 1A to 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 any of Aspects 9A and 10A, further comprising 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, a computer, a mobile device, a broadcast receiver device, or a set-top box.

Aspect 14A - The device of any 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 instructions stored thereon that, when executed, cause one or more processors to perform the method of any of Aspects 1A-8A.

Aspect 1B - A method of decoding video data, the step of constructing a total most probable mode list comprising N entries, wherein the N entries of the total most probable mode list are intra-prediction modes and the plane the mode is the first entry in the total most probable mode list, and the step of constructing a first order most probable mode list from the first Np entries in the total most probable mode list, wherein Np is less than N, constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list, and constructing a quadratic most probable mode list or a quadratic most probable mode list. determining a current intra-prediction mode for the current block of video data using the mode list; and using the current intra-prediction mode of the video data to generate a decoded block of video data. decoding the current block.

Aspect 2B - The step of determining the current intra-prediction mode is the step of decoding an index into a first-order most probable mode list or a second-order most probable mode list, wherein the index is a first-order most probable mode list or a second-order most probable mode list. The method of aspect 1B, further comprising indicating a non-planar intra prediction mode in the most probable mode list, and determining a current intra prediction mode for a current block of video data based on the index.

Aspect 3B - The context for decoding an index into a first order most probable mode list or a second order most probable mode list is to entropy decode the first bin of the index based on the coding tool currently used for the block. and entropy decoding the first bin of the index using the context.

Aspect 4B - The method of Aspect 3B, wherein the coding tool is in one of a normal intra prediction mode, an intra subpartition mode, or a multiple reference line mode.

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

Aspect 6B - The step of constructing the total most probable mode list comprises adding each intra-prediction mode from each adjacent block of the current block of video data to the total most probable mode list, and each intra-prediction mode from each adjacent block of the current block of video data. and adding a plurality of intra prediction modes offset from the intra prediction mode of to the total most probable mode list.

Aspect 7B - Adding each intra-prediction mode from each neighboring block of the current block of video data to the total most probable mode list includes the step of adding each intra-prediction mode from each adjacent block of the current block of video data to the total most probable mode list if each intra-prediction mode is available and not yet The method of aspect 6B, comprising adding each intra prediction mode from each neighboring block of the current block of video data to the total most probable mode list based on not being added.

Aspect 8B - Determining the current intra-prediction mode for the current block of video data using the first-order most probable mode list or the second-order most probable mode list comprises decoding a syntax element indicating a current most probable mode list from one of the mode lists; decoding an index into the current most probable mode list; and decoding an index into the current most probable mode list from the current most probable mode list. and determining an intra-prediction mode of.

Aspect 9B - The method of Aspect 1B, further comprising displaying a picture that includes 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 memory devices implemented in a circuit and in communication with the memory. a processor, the one or more processors constructing a total most probable mode list including N entries, the N entries of the total most probable mode list being intra prediction modes; mode is the first entry in the total most probable mode list, and constructing a first-order most probable mode list from the first Np entries in the total most probable mode list, , Np is less than N, constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list, and constructing a first order most probable mode list or determining a current intra-prediction mode for a current block of video data using a second-order most probable mode list and using the current intra-prediction mode to generate a decoded block of video data; and decoding a current block of video data.

Aspect 11B - To determine the current intra-prediction mode, the one or more processors decode an index into a first-order most probable mode list or a second-order most probable mode list, the index being 1 decoding, indicating a non-planar intra prediction mode in a next most probable mode list or a second most probable mode list; and determining a current intra prediction mode for a current block of video data based on the index. The apparatus of embodiment 10B, further configured to perform.

Aspect 12B - To decode an index into a first-order most probable mode list or a second-order most probable mode list, the one or more processors determine the first of the indexes based on the coding tool used for the current block. The apparatus of aspect 11B, further configured to determine a context for entropy decoding the bins and entropy decoding a first bin of the index using the context.

Aspect 13B - The apparatus of Aspect 12B, wherein the coding tool is in one of a normal intra prediction mode, an intra subpartition mode, or a multiple reference line mode.

Embodiment 14B - The device of Embodiment 10B, wherein N is 22 and Np is 6.

Aspect 15B - To construct a total most probable mode list, the one or more processors add each intra-prediction mode from each neighboring block of the current block of video data to the total most probable mode list; , adding a plurality of intra prediction modes offset from respective intra prediction modes from respective neighboring blocks to the total most probable mode list.

Aspect 16B - To add respective intra prediction modes from respective neighboring blocks of the current block of video data to a total most likely mode list, the one or more processors determine whether each intra prediction mode is available and , further configured to add each intra-prediction mode from each neighboring block of the current block of video data to the total most probable mode list based on not already added to the total most probable mode list; The apparatus of embodiment 15B.

Aspect 17B - To determine a current intra-prediction mode for a current block of video data using a first-order most probable mode list or a second-order most probable mode list, the one or more processors decoding a syntax element indicating a current most probable mode list from either a definite mode list or a quadratic most probable mode list; decoding an index into the current most probable mode list; The apparatus of aspect 10B, further configured to: determine a current intra prediction mode from an index to a definite mode list.

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

Aspect 19B - An apparatus configured to decode video data, the means for constructing a total most probable mode list including N entries, wherein the N entries of the total most probable mode list are construct a first-order most probable mode list from the first Np entries in the total most probable mode list, where the intra prediction mode is the planar mode and the planar mode is the first entry in the total most probable mode list. means for constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list, wherein Np is less than N; means for determining a current intra prediction mode for a current block of video data using a first order most probable mode list or a second order most probable mode list and for generating a decoded block of video data; , means for decoding a current block of video data using a current intra prediction mode.

Aspect 20B - The means for determining the current intra prediction mode is a means for decoding an index into a first order most probable mode list or a second order most probable mode list, the index being a first order most probable mode. further comprising means for indicating a non-planar intra prediction mode in a list or a quadratic most probable mode list; and means for determining a current intra prediction mode for a current block of video data based on the index. The apparatus of embodiment 19B.

Aspect 21B - The means for decoding an index into a first order most probable mode list or a second order most probable mode list entropy decodes a first bin of the index based on the coding tool used for the current block. The apparatus of aspect 20B, comprising: means for determining a context of the index; 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, the instructions comprising N entries in one or more processors configured to decode video data when executed. constructing a total most probable mode list, the N entries of the total most probable mode list are intra-predicted modes, and the planar mode is the first entry in the total most probable mode list; and constructing a first-order most probable mode list from the first Np entries in the total most probable mode list, where Np is less than N. constructing a second-order most probable mode list from the remaining (N-Np) entries in the current block of video data using the first-order most probable mode list or the second-order most probable mode list. and decoding the current block of video data using the current intra prediction mode to generate a decoded block of video data. Readable storage medium.

Aspect 23B - To determine the current intra-prediction mode, the instructions cause the one or more processors to decode an index into a first-order most probable mode list or a second-order most probable mode list, the instructions including: Decodes and determines the current intra-prediction mode for the current block of video data based on the index, which indicates the non-planar intra-prediction mode in the first-order most probable mode list or the second-order most probable mode list. Embodiment 22B's non-transitory computer-readable storage medium further comprises:

Aspect 24B - To decode an index into a first-order most probable mode list or a second-order most probable mode list, an instruction instructs one or more processors to determine the index of the index based on the coding tool currently used for the block. The non-transitory computer-readable storage medium of aspect 23B further causes determining a context for entropy decoding the first bin and using the context to entropy decode the first bin of the index.

Aspect 25B - An apparatus configured to encode video data, the one or more being implemented in a circuit and in communication with a memory configured to store a current block of video data. and the one or more processors constructing a total most probable mode list including N entries, the N entries of the total most probable mode list being intra prediction modes; The planar mode is the first entry in the total most probable mode list, and constructing the first order most probable mode list from the first Np entries in the total most probable mode list. , Np is less than N, constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list, and constructing a first order most probable mode list. or determining the current intra-prediction mode for the current block of video data using the quadratic most probable mode list and selecting the current intra-prediction mode to generate the encoded block of video data. and encoding a current block of video data using an apparatus.

Aspect 26B - The one or more processors encode an index into a first-order most probable mode list or a second-order most probable mode list, wherein the index The apparatus of aspect 25B, further configured to perform encoding indicating a non-planar intra prediction mode in the mode list.

Aspect 27B - To encode an index into a first-order most probable mode list or a second-order most probable mode list, the one or more processors select the first of the indexes based on the coding tool used for the current block. The apparatus of aspect 26B, further configured to: determine a context for entropy encoding a bin of the index; and entropy encode a first bin of the index using the context.

Aspect 28B - The apparatus of Aspect 27B, wherein the coding tool is in one of a normal intra prediction mode, an intra subpartition mode, or a multiple reference line mode.

Embodiment 29B - The device of Embodiment 25B, wherein N is 22 and Np is 6.

Aspect 30B - To construct a total most probable mode list, the one or more processors add each intra-prediction mode from each neighboring block of the current block of video data to the total most probable mode list; , adding a plurality of intra prediction modes offset from respective intra prediction modes from respective neighboring blocks to the total most probable mode list.

Aspect 31B - To add respective intra prediction modes from respective neighboring blocks of the current block of video data to a total most probable mode list, the one or more processors determine whether each intra prediction mode is available and , further configured to add each intra-prediction mode from each neighboring block of the current block of video data to the total most probable mode list based on not already added to the total most probable mode list; The apparatus of embodiment 25B.

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

Aspect 1C - A method of decoding video data, the step of constructing a total most probable mode list comprising N entries, wherein the N entries of the total most probable mode list are intra-prediction modes and the plane the mode is the first entry in the total most probable mode list, and the step of constructing a first order most probable mode list from the first Np entries in the total most probable mode list, wherein Np is less than N, constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list, and constructing a quadratic most probable mode list or a quadratic most probable mode list. determining a current intra-prediction mode for the current block of video data using the mode list; and using the current intra-prediction mode of the video data to generate a decoded block of video data. decoding the current block.

Aspect 2C - The step of determining the current intra prediction mode is the step of decoding an index into a first-order most probable mode list or a second-order most probable mode list, wherein the index is a first-order most probable mode list or a second-order most probable mode list. The method of aspect 1C, further comprising indicating a non-planar intra prediction mode in the most probable mode list and determining a current intra prediction mode for the current block of video data based on the index.

Aspect 3C - Context for decoding an index into a first-order most probable mode list or a second-order most probable mode list to entropy decode the first bin of the index based on the coding tool currently used for the block. and entropy decoding the first bin of the index using the context.

Aspect 4C - The method of Aspect 3C, wherein the coding tool is in one of a normal intra prediction mode, an intra subpartition mode, or a multiple reference line mode.

Embodiment 5C - The method of any of Embodiments 1C to 4C, wherein N is 22 and Np is 6.

Aspect 6C - The step of constructing the total most probable mode list comprises adding each intra-prediction mode from each adjacent block of the current block of video data to the total most probable mode list, and each intra-prediction mode from each adjacent block of the current block of video data. and adding a plurality of intra-prediction modes offset from the intra-prediction modes of to the total most probable mode list.

Aspect 7C - Adding each intra prediction mode from each neighboring block of the current block of video data to the total most probable mode list includes the step of adding each intra prediction mode from each adjacent block of the current block of video data The method of aspect 6C, comprising adding each intra prediction mode from each neighboring block of the current block of video data to the total most probable mode list based on not being added.

Aspect 8C - Determining the current intra-prediction mode for the current block of video data using the first-order most probable mode list or the second-order most probable mode list comprises decoding a syntax element indicating a current most probable mode list from one of the mode lists; decoding an index into the current most probable mode list; and decoding an index into the current most probable mode list from the current most probable mode list. and determining an intra-prediction mode of.

Aspect 9C - The method of any of Aspects 1C-8C, further comprising displaying a picture that includes 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 memory devices implemented in a circuit and in communication with the memory. a processor, the one or more processors constructing a total most probable mode list including N entries, the N entries of the total most probable mode list being intra prediction modes; mode is the first entry in the total most probable mode list, and constructing a first-order most probable mode list from the first Np entries in the total most probable mode list, , Np is less than N, constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list, and constructing a first order most probable mode list or determining a current intra-prediction mode for a current block of video data using a second-order most probable mode list and using the current intra-prediction mode to generate a decoded block of video data; and decoding a current block of video data.

Aspect 11C - To determine the current intra-prediction mode, the one or more processors decode an index into a first-order most probable mode list or a second-order most probable mode list, the index being 1 decoding, indicating a non-planar intra prediction mode in a next most probable mode list or a second most probable mode list; and determining a current intra prediction mode for a current block of video data based on the index. The apparatus of embodiment 10C, further configured to perform.

Aspect 12C - To decode the index into the first-order most probable mode list or the second-order most probable mode list, the one or more processors decode the index based on the coding tool used for the current block of video data. The apparatus of aspect 11C, further configured to determine a context for entropy decoding a first bin and entropy decoding a first bin of the index using the context.

Aspect 13C - The apparatus of Aspect 12C, wherein the coding tool is in one of a normal intra prediction mode, an intra subpartition mode, or a multiple reference line mode.

Embodiment 14C - The device of any of embodiments 10C to 13C, wherein N is 22 and Np is 6.

Aspect 15C - To build a total most probable mode list, the one or more processors add each intra-prediction mode from each neighboring block of the current block of video data to the total most probable mode list; , adding the plurality of intra-prediction modes offset from each intra-prediction mode from each neighboring block to the total most probable mode list, the apparatus of any of aspects 10C-14C. .

Aspect 16C - To add respective intra prediction modes from respective neighboring blocks of the current block of video data to a total most probable mode list, the one or more processors determine whether each intra prediction mode is available and , further configured to add each intra-prediction mode from each neighboring block of the current block of video data to the total most probable mode list based on not already added to the total most probable mode list; The device of embodiment 15C.

Aspect 17C - To determine a current intra-prediction mode for a current block of video data using a first-order most probable mode list or a second-order most probable mode list, the one or more processors decoding a syntax element indicating a current most probable mode list from either a definite mode list or a quadratic most probable mode list; decoding an index into the current most probable mode list; 16. The apparatus of any of aspects 10C-16C, further configured to: determine a current intra prediction mode from an index into a reliable mode list.

Aspect 18C - The apparatus of any of Aspects 10C-17C, further comprising a display configured to display a picture that includes 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 implemented in a circuit and in communication with the memory. and the one or more processors constructing a total most probable mode list including N entries, the N entries of the total most probable mode list being intra prediction modes; The planar mode is the first entry in the total most probable mode list, and constructing the first order most probable mode list from the first Np entries in the total most probable mode list. , Np is less than N, constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list, and constructing a first order most probable mode list. or determining the current intra-prediction mode for the current block of video data using the quadratic most probable mode list and selecting the current intra-prediction mode to generate the encoded block of video data. and encoding a current block of video data using an apparatus.

Aspect 20C - The one or more processors encode an index into a first-order most probable mode list or a second-order most probable mode list, the index into a first-order most probable mode list or a second-order most probable mode list. The apparatus of aspect 19C, further configured to perform encoding indicating a non-planar intra prediction mode in the mode list.

Aspect 21C - To encode the index into the first-order most probable mode list or the second-order most probable mode list, the one or more processors encode the index based on the coding tool used for the current block of video data. The apparatus of aspect 20C, further configured to: determine a context for entropy encoding a first bin of the index; and entropy encode a first bin of the index using the context. .

Aspect 22C - The apparatus of Aspect 21C, wherein the coding tool is in one of a normal intra prediction mode, an intra subpartition mode, or a multiple reference line mode.

Embodiment 23C - The device of any of embodiments 19C-22C, wherein N is 22 and Np is 6.

Aspect 24C - To construct a total most probable mode list, the one or more processors add each intra-prediction mode from each neighboring block of the current block of video data to the total most probable mode list; , adding a plurality of intra-prediction modes offset from respective intra-prediction modes from respective neighboring blocks to the total most probable mode list. .

Aspect 25 - The one or more processors determine whether each intra-prediction mode is available and adds each intra-prediction mode from each neighboring block of the current block of video data to a total most probable mode list. , further configured to add each intra-prediction mode from each neighboring block of the current block of video data to the total most probable mode list based on not already added to the total most probable mode list; The device of any of aspects 19C to 24C.

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

Depending on the example, some acts or events of any of the techniques described herein may be performed in different sequences, and may be added, integrated, or excluded entirely (e.g. , it is recognized that not all acts or events described may be necessary for the practice of the technique). Further, in some examples, acts or events may be performed concurrently rather than sequentially, eg, through multi-threaded processing, interrupt processing, or multiple processors.

In one or more examples, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over a computer-readable medium as one or more instructions or code for execution by a hardware-based processing unit. . Computer-readable media refers to a computer-readable storage medium that corresponds to a tangible medium such as a data storage medium or communication protocol including any medium that facilitates transfer of a computer program from one place to another according to, e.g., a communication protocol. may include a medium. Thus, 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. The data storage medium can be any available data storage medium 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. It can be any medium. A computer program product may include a computer readable medium.

By way of example and not limitation, such computer-readable storage medium may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage device, flash memory, or a memory containing instructions or data structures. Any other medium that can be used to store desired program code in the form and that can be accessed by a computer can be included. 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. It should be understood, however, that computer-readable storage media and data storage media do not include connections, carrier waves, signals or other transitory media, and instead refer to non-transitory tangible storage media. As used herein, "disk" and "disc" refer to compact disc (disc) (CD), Laserdisc (registered trademark) (disc), optical disc (disc), digital versatile disc (disc) (DVD). ), floppy disks (disks), and Blu-ray disks (discs), with disks typically reproducing data magnetically and discs reproducing data optically using lasers. Combinations of the above should also be included within the scope of computer-readable media.

The instructions may be executed by one or more processors, such as one or more DSPs, general purpose microprocessors, ASICs, FPGAs, or other equivalent integrated or discrete logic circuits. Accordingly, the terms "processor" and "processing circuitry" as used herein may refer to any of the structures described above, or any other structure suitable for implementing 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 in combination codecs. May be incorporated. Also, the techniques may be implemented entirely 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 wireless handsets, integrated circuits (ICs) or sets of ICs (eg, chipsets). Although various components, modules, or units are described in this disclosure to emphasize functional aspects of devices configured to perform the disclosed techniques, they do not necessarily require implementation by different hardware units. Not necessarily. Rather, as explained above, the various units may be combined in a codec hardware unit, or include one or more processors as explained above, together with suitable software and/or firmware. It may also be provided by a collection of interoperable hardware units.

We have discussed various examples. These and other examples are within the scope of the following claims.

100 Video Encoding and Decoding Systems, Systems
102 Source device
104 Video Source
106 Memory
108 output interface
110 Computer-readable media
112 Storage devices
114 File server
116 Destination Device
118 Display devices
120 memory
122 input interface
130 Quadrant binary tree (QTBT) structure, QTBT structure
132 Coding Tree Unit (CTU), CTU
200 video encoder
202 Mode selection unit
204 Residual generation unit
206 Conversion processing unit
208 Quantization unit
210 Inverse quantization unit
212 Inverse transformation processing unit
214 Reconfiguration unit
216 Filter unit
218 Decoded Picture Buffer (DPB), DPB
220 entropy coding units
222 Motion estimation unit
224 Motion Compensation Unit
226 Intra prediction unit
230 video data memory
300 video decoder
302 Entropy decoding unit
304 Prediction processing unit
306 Inverse quantization unit
308 Inverse conversion processing unit
310 Reconfiguration unit
312 Filter unit
314 Decoded Picture Buffer (DPB), DPB
316 Motion compensation unit
318 Intra prediction unit
320 coded picture buffer (CPB) memory, CPB memory
400 C.U.
402 C.U.

Claims (32)

A method for decoding video data, the method comprising:
constructing a total most probable mode list including N entries, wherein the N entries of the total most probable mode list are intra-prediction modes, and the planar mode is one of the total most probable mode lists in the total most probable mode list. The first entry, step,
constructing a first-order most probable mode list from the first Np entries in the total most probable mode list, where Np is less than N;
constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list;
determining a current intra prediction mode for a current block of video data using the first order most probable mode list or the second order most probable mode list;
decoding the current block of video data using the current intra prediction mode to generate a decoded block of video data. The step of determining the current intra prediction mode comprises:
decoding an index into the first-order most probable mode list or the second-order most probable mode list, the index being a non-plane in the first-order most probable mode list or the second-order most probable mode list; Indicating an intra prediction mode, a step;
2. The method of claim 1, further comprising: determining the current intra prediction mode for the current block of video data based on the index. decoding the index into the first order most probable mode list or the second order most probable mode list,
determining a context for entropy decoding the first bin of the index based on a coding tool used for the current block of video data;
and entropy decoding the first bin of the index using the context. 4. The method of claim 3, wherein the coding tool is in one of a normal intra prediction mode, an intra subpartition mode, or a multiple reference line mode. 2. The method of claim 1, wherein N is 22 and Np is 6. The step of constructing the total most probable mode list comprises:
adding respective intra prediction modes from respective neighboring blocks of the current block of video data to the total most probable mode list;
and adding a plurality of intra prediction modes offset from the respective intra prediction modes from the respective neighboring blocks to the total most probable mode list. adding the respective intra prediction modes from the respective neighboring blocks of the current block of video data to the total most probable mode list, wherein the respective intra prediction modes are available and the total most probable mode 7. Adding the respective intra prediction modes from the respective neighboring blocks of the current block of video data to the total most probable mode list based on not already added to the list. Method described. determining the current intra prediction mode for the current block of video data using the first order most probable mode list or the second order most probable mode list;
decoding a syntax element indicating a current most probable mode list from either the first order most probable mode list or the second order most probable mode list;
decoding the index into the current most probable mode list;
and determining the current intra-prediction mode from the index into the current most probable mode list. 2. The method of claim 1, further comprising displaying a picture including the decoded block of video data. An apparatus configured to decode video data, the apparatus comprising:
a memory configured to store a current block of video data;
one or more processors implemented in circuitry and in communication with the memory, the one or more processors comprising:
constructing a total most probable mode list including N entries, wherein the N entries of the total most probable mode list are intra-prediction modes, and the planar mode is one of the total most probable mode lists; The first entry, building, and
constructing a first order most probable mode list from the first Np entries in the total most probable mode list, where Np is less than N;
constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list;
determining a current intra prediction mode for a current block of video data using the first order most probable mode list or the second order most probable mode list;
decoding the current block of video data using the current intra prediction mode to generate a decoded block of video data. to determine the current intra prediction mode, the one or more processors:
decoding an index into the first-order most probable mode list or the second-order most probable mode list, wherein the index is a non-plane in the first-order most probable mode list or the second-order most probable mode list; decoding and indicating an intra prediction mode;
11. The apparatus of claim 10, further configured to: determine the current intra prediction mode for the current block of video data based on the index. In order to decode the index into the first order most probable mode list or the second order most probable mode list, the one or more processors:
determining a context for entropy decoding the first bin of the index based on a coding tool used for the current block of video data;
12. The apparatus of claim 11, further configured to entropy decode the first bin of the index using the context. 13. The apparatus of claim 12, wherein the coding tool is in one of a normal intra prediction mode, an intra subpartition mode, or a multiple reference line mode. 11. The device of claim 10, wherein N is 22 and Np is 6. In order to construct the total most probable mode list, the one or more processors:
adding respective intra prediction modes from respective neighboring blocks of the current block of video data to the total most probable mode list;
11. The apparatus of claim 10, further configured to: add a plurality of intra prediction modes offset from the respective intra prediction modes from the respective neighboring blocks to the total most probable mode list. . the one or more processors for adding the respective intra prediction modes from the respective neighboring blocks of the current block of video data to the total most probable mode list;
the respective intra prediction modes from the respective neighboring blocks of the current block of video data based on the respective intra prediction modes being available and not yet added to the total most probable mode list; 16. The apparatus of claim 15, further configured to add to the total most probable mode list. the one or more processors to determine the current intra prediction mode for the current block of video data using the first order most probable mode list or the second order most probable mode list;
decoding a syntax element indicating a current most probable mode list from either the first order most probable mode list or the second order most probable mode list;
decoding an index into the current most probable mode list;
11. The apparatus of claim 10, further configured to: determine the current intra prediction mode from the index into the current most probable mode list. 11. The apparatus of claim 10, further comprising a display configured to display a picture including the decoded block of video data. An apparatus configured to decode video data, the apparatus comprising:
Means for constructing a total most probable mode list including N entries, wherein the N entries of the total most probable mode list are intra prediction modes, and the planar mode is the total most probable mode list of the total most probable mode list. The first entry in the means and
means for constructing a first order most probable mode list from the first Np entries in the total most probable mode list, where Np is less than N;
means for constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list;
means for determining a current intra prediction mode for a current block of video data using the first order most probable mode list or the second order most probable mode list;
and means for decoding the current block of video data using the current intra prediction mode to generate a decoded block of video data. The means for determining the current intra prediction mode,
Means for decoding an index into the first most probable mode list or the second most probable mode list, the index being one of the first most probable mode list or the second most probable mode list. means for indicating a non-planar intra prediction mode;
20. The apparatus of claim 19, further comprising means for determining the current intra prediction mode for the current block of video data based on the index. The means for decoding the index into the first order most probable mode list or the second order most probable mode list,
means for determining a context for entropy decoding the first bin of the index based on a coding tool used for the current block of video data;
and means for entropy decoding the first bin of the index using the context. a non-transitory computer-readable storage medium having instructions stored thereon, the instructions, when executed, being configured to decode video data;
constructing a total most probable mode list including N entries, wherein the N entries of the total most probable mode list are intra-prediction modes, and the planar mode is one of the total most probable mode lists; The first entry, building, and
constructing a first order most probable mode list from the first Np entries in the total most probable mode list, where Np is less than N;
constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list;
determining a current intra prediction mode for a current block of video data using the first order most probable mode list or the second order most probable mode list;
and decoding the current block of video data using the current intra prediction mode to generate a decoded block of video data. to determine the current intra prediction mode, the instructions cause the one or more processors to:
decoding an index into the first-order most probable mode list or the second-order most probable mode list, wherein the index is a non-plane in the first-order most probable mode list or the second-order most probable mode list; decoding and indicating an intra prediction mode;
23. The non-transitory computer-readable storage medium of claim 22, further comprising: determining the current intra prediction mode for the current block of video data based on the index. The instructions cause the one or more processors to decode the index into the first order most probable mode list or the second order most probable mode list.
determining a context for entropy decoding the first bin of the index based on a coding tool used for the current block of video data;
24. The non-transitory computer-readable storage medium of claim 23, further comprising entropy decoding the first bin of the index using the context. An apparatus configured to encode video data, the apparatus comprising:
a memory configured to store a current block of video data;
one or more processors implemented in circuitry and in communication with the memory, the one or more processors comprising:
constructing a total most probable mode list including N entries, wherein the N entries of the total most probable mode list are intra-prediction modes, and the planar mode is one of the total most probable mode lists; The first entry, building, and
constructing a first order most probable mode list from the first Np entries in the total most probable mode list, where Np is less than N;
constructing a quadratic most probable mode list from the remaining (N-Np) entries in the total most probable mode list;
determining a current intra prediction mode for a current block of video data using the first order most probable mode list or the second order most probable mode list;
and encoding the current block of video data using the current intra prediction mode to generate an encoded block of video data. the one or more processors encoding an index into the first order most probable mode list or the second order most probable mode list, wherein the index is one of the first order most probable mode list or the second order most probable mode list; 26. The apparatus of claim 25, further configured to indicate and encode a non-planar intra prediction mode in the next most probable mode list. the one or more processors to encode the index into the first order most probable mode list or the second order most probable mode list;
determining a context for entropy encoding the first bin of the index based on a coding tool used for the current block of video data;
27. The apparatus of claim 26, further configured to entropy encode the first bin of the index using the context. 28. The apparatus of claim 27, wherein the coding tool is in one of a normal intra prediction mode, an intra subpartition mode, or a multiple reference line mode. 26. The device of claim 25, wherein N is 22 and Np is 6. In order to construct the total most probable mode list, the one or more processors:
adding respective intra prediction modes from respective neighboring blocks of the current block of video data to the total most probable mode list;
26. The apparatus of claim 25, further configured to: add a plurality of intra prediction modes offset from the respective intra prediction modes from the respective neighboring blocks to the total most probable mode list. . the one or more processors for adding the respective intra prediction modes from the respective neighboring blocks of the current block of video data to the total most probable mode list;
the respective intra prediction modes from the respective neighboring blocks of the current block of video data based on the respective intra prediction modes being available and not yet added to the total most probable mode list; 31. The apparatus of claim 30, further configured to add to the total most probable mode list. 26. The apparatus of claim 25, further comprising a camera configured to capture a picture including the current block of video data.

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