Geometric partitioning modes in video coding.

Abstract

A method for encoding or decoding video data includes determining that a geometric partitioning mode is enabled for a current block of video data, the geometric partitioning mode including a plurality of partitioning modes each defining an edge for partitioning; determining, for each partitioning mode among at least two of the plurality of partitioning modes, a respective cost associated with the respective partitioning mode; constructing a mapping list including index values ​​respectively associated with values ​​indicative of the respective partitioning modes based on the respective costs associated with the respective partitioning modes, wherein a lower index value is associated with a first partitioning mode having a lower cost than a second partitioning mode having a higher index value; determining a partitioning mode from among the plurality of partitioning modes in the mapping list; and reconstructing the current block of video data based on the partitioning mode.

Description

[Technical field]

[0001]

[0001] This application claims priority to U.S. Patent Application No. 18 / 068,767, filed December 20, 2022, and U.S. Provisional Patent Application No. 63 / 266,386, filed January 04, 2022, the entire contents of both of which are incorporated herein by reference. U.S. Patent Application No. 18 / 068,767, filed December 20, 2022, claims the benefit of U.S. Provisional Patent Application No. 63 / 266,386, filed January 4, 2022.

[0002]

[0002] This disclosure relates to video encoding and decoding. [Background technology]

[0003] Digital video capabilities may be incorporated into a wide range of devices, including digital televisions, digital direct broadcast systems, wireless broadcast systems, personal digital assistants (PDAs), laptop or desktop computers, tablet computers, e-book readers, digital cameras, digital recording devices, digital media players, video gaming devices, video game consoles, cellular or satellite radio telephones, so-called "smartphones," video teleconferencing devices, video streaming devices, etc. Digital video devices implement video coding techniques such as those described in standards defined by MPEG-2, MPEG-4, ITU-T H.263, ITU-T H.264 / MPEG-4, Part 10, Advanced Video Coding (AVC), ITU-T H.265 / High Efficiency Video Coding (HEVC), ITU-T H.266 / Generic Video Coding (VVC), and extensions to such standards, as well as proprietary video codecs / formats such as AOMedia Video1 (AV1) developed by the Alliance for Open Media. Video devices may implement such video coding techniques to more efficiently transmit, receive, encode, decode, and / or store digital video information.

[0004]

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

[0005]

[0005] Generally, this disclosure describes techniques for signaling and parsing syntax (e.g., partition mode, candidate index, MVD (motion vector differential) offset) used to identify parameters of a geometric partitioning mode (e.g., geometric partitioning mode (GEO), GEO+MMVD (merged motion vector differential) mode, GEO+TM (template matching) mode). A geometric partitioning mode may also be referred to as a geometric partitioning mode (GPM), GPM+MMVD, or GPM+TM. Example techniques of this disclosure may optimize the syntax used to signal parameters of a geometric partitioning mode. Such techniques may be applied to any of the existing video codecs, such as HEVC (High Efficiency Video Coding), VVC (Versatile Video Coding), or Essential Video Coding (EVC), or may be an efficient coding tool in future video coding standards (e.g., Enhanced Compression Model (ECM)).

[0006]

[0006] The GPM includes multiple partition modes, each of which defines an edge that divides a current block into two or more partitions. A video encoder signals information indicating the partition mode, a video decoder receives information indicating the partition mode, and both the video encoder and the video decoder partition the current block in the same manner. This disclosure describes an example method for determining which partition mode is used to encode or decode a current block in a manner that exploits the likelihood that the current block is encoded or decoded according to an edge of a particular partition mode.

[0007]

[0007] The likelihood that a partition mode will be used may vary and may be based on cost (e.g., in terms of rate distortion or number of bits that need to be signaled, etc.). That is, a partition mode with a lower cost is more likely to be used compared to a partition mode with a higher cost. In one or more examples, a video encoder and a video decoder may build a mapping list having values ​​indicating each partition mode based on the respective costs associated with each partition mode. The video encoder may signal an index value to the mapping list that identifies a value stored in the mapping list, and based on the identified value, the video decoder may determine one of the multiple partition modes.

[0008]

[0008] In one or more examples, signaling a smaller index value may require fewer bits than signaling a larger index value. By constructing the mapping list such that a more likely partition mode to be used is associated with a smaller index value, a video encoder is more likely to signal a smaller index value in the mapping list compared to when the mapping list is constructed without considering the likelihood of the partition mode to be used. In this manner, the example technique may provide practical applications for improving bandwidth utilization (e.g., facilitating reduced bandwidth utilization) in the art of video coding.

[0009]

[0009] In one example, the present disclosure describes a method for encoding or decoding video data, the method including: determining that a geometric partitioning mode is enabled for a current block of video data, the geometric partitioning mode including a plurality of partitioning modes each defining an edge for partitioning; determining, for each partitioning mode among at least two of the plurality of partitioning modes, a respective cost associated with the respective partitioning mode; constructing a mapping list including index values ​​respectively associated with values ​​indicative of the respective partitioning modes based on the respective costs associated with the respective partitioning modes, wherein a lower index value in the mapping list is associated with a first partitioning mode having a lower cost than a second partitioning mode having a higher index value in the mapping list; determining a partitioning mode from among the plurality of partitioning modes in the mapping list; and reconstructing the current block of video data based on the partitioning mode.

[0010]

[0010] In one example, the disclosure describes a device for encoding or decoding video data, the device comprising: a memory configured to store the video data; and a processing circuit coupled to the memory, wherein the processing circuit is configured to: determine that a geometric partitioning mode is enabled for a current block of video data, the geometric partitioning mode including a plurality of partitioning modes each defining an edge for partitioning; for each partitioning mode among at least two of the plurality of partitioning modes, a respective cost associated with the respective partitioning mode; construct a mapping list including index values ​​respectively associated with values ​​indicative of the respective partitioning modes based on the respective costs associated with the respective partitioning modes, a lower index value in the mapping list is associated with a first partitioning mode having a lower cost than a second partitioning mode having a higher index value in the mapping list; determine a partitioning mode among the plurality of partitioning modes in the mapping list; and reconstruct the current block of video data based on the partitioning mode.

[0011]

[0011] In one example, the disclosure describes a computer-readable storage medium having stored thereon instructions which, when executed, cause one or more processors for encoding or decoding video data to determine that a geometric partitioning mode is enabled for a current block of video data, the geometric partitioning mode including a plurality of partitioning modes each defining an edge for partitioning, for each partitioning mode among at least two of the plurality of partitioning modes, determine a respective cost associated with the respective partitioning mode, construct a mapping list including index values ​​respectively associated with values ​​indicative of the respective partitioning modes based on the respective costs associated with the respective partitioning modes, a lower index value in the mapping list is associated with a first partitioning mode having a lower cost than a second partitioning mode having a higher index value in the mapping list, determine a partitioning mode among the plurality of partitioning modes in the mapping list, and reconstruct the current block of video data based on the partitioning mode.

[0012]

[0012] In one example, the disclosure describes an apparatus for encoding or decoding video data, the apparatus including means for determining that a geometric partitioning mode is enabled for a current block of video data, the geometric partitioning mode including a plurality of partitioning modes each defining an edge for partitioning; means for determining, for each partitioning mode among at least two of the plurality of partitioning modes, a respective cost associated with the respective partitioning mode; means for constructing a mapping list including index values ​​respectively associated with values ​​indicative of the respective partitioning modes based on the respective costs associated with the respective partitioning modes, wherein a lower index value in the mapping list is associated with a first partitioning mode having a lower cost than a second partitioning mode having a higher index value in the mapping list; means for determining a partitioning mode from among the plurality of partitioning modes in the mapping list; and means for reconstructing the current block of video data based on the partitioning mode.

[0013] The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will become apparent from the description, drawings, and claims. [Brief description of the drawings]

[0014]

Figure 1

[0014] FIG. 1 is a block diagram illustrating an example video encoding and decoding system in which techniques of this disclosure may be implemented.

Figure 2

[0015] 1 is a block diagram illustrating an example video encoder capable of implementing the techniques of this disclosure.

Figure 3

[0016] 1 is a block diagram illustrating an example video decoder capable of implementing the techniques of this disclosure.

Figure 4A

[0017] 1A and 1B are conceptual diagrams illustrating spatially adjacent motion vector (MV) candidates for merge mode and advanced motion vector prediction (AMVP) mode, respectively.

Figure 4B

Figure 5A

[0018] 1A and 1B are conceptual diagrams illustrating temporal motion vector candidate (TMVP) scaling and motion vector scaling, respectively.

Figure 5B

Figure 6

[0019] FIG. 1 is a conceptual diagram showing an example of partitioning for the geometric partitioning mode (GEO).

Figure 7

[0020] FIG. 2 is a conceptual diagram illustrating an example template and reference samples for the template in a reference picture.

Figure 8

[0021] 1 is a conceptual diagram illustrating an example template for a block and a reference sample for the template, along with sub-block motion using motion information of the sub-block of a current block.

Figure 9

[0022] FIG. 13 is a conceptual diagram illustrating template matching in a search area around an initial MV.

Figure 10A

[0023] FIG. 13 is a conceptual diagram illustrating an example of generating a reference template for determining the cost of a partitioning mode.

Figure 10B

Figure 10C

Figure 10D

Figure 11

[0024] 11 is a flow chart illustrating an example of building a mapping list for a split mode.

Figure 12

[0025] 4 is a flowchart illustrating an example method of decoding according to example techniques described in this disclosure.

Figure 13

[0026] 4 is a flowchart illustrating an example method of encoding according to example techniques described in this disclosure.

Figure 14

[0027] 1 is a flowchart illustrating an example method for decoding video data with reference picture resampling. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015]

[0028] In the geometric partitioning mode (GEO) or (GPM), the current block is divided into at least two parts by one or more geometrically located straight edge(s). In this disclosure, the acronyms GEO and GPM are interchangeable.

[0016]

[0029] The straight edge may intersect with two different edges of the current block (e.g., a line from the top edge to the bottom edge at a different angle, a line from the right edge to the top edge at a different angle, a line from the right edge to the bottom edge at a different angle, a line from the right edge to the left edge at a different angle, a line from the left edge to the top edge at a different angle, and a line from the left edge to the bottom edge at a different angle). Each of these exemplary edges (e.g., lines) may be considered as a partition mode of GEO. The video encoder may signal information indicating the partition mode to the video decoder.

[0017]

[0030] Some techniques utilize a fixed-length coding structure of the GEO partition mode, where each partition mode is considered to be equally probable. However, such techniques may be suboptimal in terms of codeword length, since they may not utilize information from neighboring pixels (e.g., causal neighboring pixels of a reference picture) to predict the edge direction (e.g., partition mode) of the edge of the current block. Thus, in such techniques, syntax designs from the GEO partition mode may result in signaling longer codewords than necessary, which may result in inefficient bandwidth utilization.

[0018]

[0031] This disclosure describes example techniques for signaling and analyzing information about GEO partitioning modes that may promote efficient bandwidth utilization. Example techniques may utilize one or more of syntax permutations for GEO partitioning modes using grouping and / or cost (e.g., template matching (TM) cost) based syntax permutations for GEO partitioning modes. This disclosure also describes techniques related to cost calculation, use of GEO weights for blending reference block templates, application of GEO+TM modes, interactions between reference picture resampling and TM cost-based GEO partitioning mode permutations, and various extensions.

[0019]

[0032] In some existing techniques, a video encoder signals a value (e.g., a value between 0 and 63), where each value is associated with a particular partitioning mode. The video decoder may then partition the current block based on edges defined by the partitioning mode associated with the signaled value.

[0020]

[0033] This disclosure describes example methods for constructing a mapping list that sorts the partition modes such that partition modes that are more likely to be used are arranged to have a lower index value into the mapping list than partition modes that are less likely to be used. For example, assume that partition mode 15 (e.g., a partition mode having a value associated with 15) is more likely to be a partition mode than partition mode 5. In this example, the video encoder and video decoder may construct the mapping list such that partition mode 15 is associated with a lower index value (e.g., index 0 in the mapping list) than partition mode 5 (e.g., index 4 in the mapping list).

[0021]

[0034] To determine that a partition mode is more likely to be used than another partition mode, the video encoder and video decoder may determine a respective cost associated with the partition mode. For example, for each partition mode among at least two of the plurality of partition modes (e.g., a subset or all of the plurality of partition modes), the video encoder and video decoder may determine a respective cost associated with the respective partition mode. The video encoder and video decoder may construct a mapping list having values ​​indicative of the respective partition modes (e.g., partition mode 5 and partition mode 15 from the above example) based on the respective costs associated with the respective partition modes (e.g., a partition mode with a lower cost is identified first and has a lower index value in the mapping list, and a partition mode with a higher cost is identified later and has a higher index value in the mapping list). That is, the video encoder and video decoder may construct a mapping list including index values ​​respectively associated with values ​​indicative of the respective partition modes based on the respective costs associated with the respective partition modes, and a lower index value in the mapping list is associated with a first partition mode having a lower cost than a second partition mode having a higher index value in the mapping list.

[0022]

[0035] One exemplary method of determining the cost of a partition mode is to determine a respective template based on the respective partition mode. In one or more examples, the respective templates for determining the respective costs of each respective partition mode may be formed based on samples adjacent to the respective reference blocks, where the reference blocks are identified by the motion vectors of the partitions of the current block. For example, each partition mode may define which samples from the samples adjacent to the respective reference blocks are used to form the respective templates.

[0023]

[0036] The video encoder and the video decoder may compare each template for each partition mode with a current template for the current block to determine a respective cost of each partition mode. For example, the video encoder and the video decoder may generate a first reference template for a first partition mode and compare the first reference template with the current template to determine a first cost of the first partition mode. The video encoder and the video decoder may generate a second reference template for a second partition mode and compare the second reference template with the current template to determine a second cost of the second partition mode.

[0024]

[0037] The video encoder and the video decoder may place a value identifying the first partition mode and a value identifying the second partition mode in the mapping list based on the first cost and the second cost. For example, if the first cost is less than the second cost, the video encoder and the video decoder may include the first partition mode in the mapping list at a lower index value than the second partition mode. If the first cost is greater than the second cost, the video encoder and the video decoder may include the first partition mode in the mapping list at a higher index value than the second partition mode.

[0025]

[0038] The video encoder and the video decoder may repeat such operations for all or a subset of the multiple partition modes to build a mapping list. In some examples, the mapping list may identify the 32 most probable partition modes.

[0026]

[0039] In this way, both the video encoder and the video decoder may build the same mapping list. The video encoder may signal an index value to the mapping list that the video decoder uses to determine the partition mode for the current block. The video decoder may then partition the current block based on edges defined by the partition mode and reconstruct the current block based on the partition mode (e.g., the determined partition mode).

[0027]

[0040] 1 is a block diagram illustrating an example video encoding and decoding system 100 that may implement techniques of this disclosure. The techniques of this disclosure are generally directed to coding (encoding and / or decoding) video data. In general, video data includes any data for processing video. Thus, video data may include raw uncoded video, coded video, decoded (e.g., reconstructed) video, and video metadata, such as signaling data.

[0028]

[0041] 1, in this example, system 100 includes a source device 102 that provides encoded video data to be decoded and displayed by a destination device 116. Specifically, source device 102 provides the video data to destination device 116 via a computer-readable medium 110. Source device 102 and destination device 116 may comprise any of a wide range of devices, including 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, video gaming consoles, video streaming devices, broadcast receiver devices, and the like. In some cases, source device 102 and destination device 116 may be capable of wireless communication and thus may be referred to as wireless communication devices.

[0029]

[0042] 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. According to this disclosure, video encoder 200 of source device 102 and video decoder 300 of destination device 116 may be configured to apply techniques for syntax ordering in geometric partitioning mode (GEO), also referred to as GPM, in video coding, such as techniques for signaling and parsing syntax (e.g., partition mode, candidate index, MVD (motion vector difference) offset) used to identify parameters of geometric partitioning mode (e.g., geometric partitioning mode (GEO), GEO+MMVD (merged motion vector difference) mode, GEO+TM (template matching) mode). Thus, source device 102 represents an example of a video encoding device, while destination device 116 represents an example of a video decoding device. In other examples, the source and destination devices 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.

[0030]

[0043] The system 100 as shown in FIG. 1 is only an example. In general, any digital video encoding and / or decoding device may perform the techniques for signaling and parsing the syntax used to identify parameters of the geometric partitioning mode. The source device 102 and the destination device 116 are only examples of coding devices, such that the source device 102 generates coded video data for transmission to the destination device 116. This disclosure refers to devices that perform coding (encoding and / or decoding) of data as "coding" devices. Thus, the video encoder 200 and the video decoder 300 represent examples of coding devices, specifically, video encoders and video decoders, respectively. In some examples, the source device 102 and the destination device 116 may operate substantially symmetrically, such that each of the source device 102 and the 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, video streaming, video playback, video broadcasting, or video telephony.

[0031]

[0044] In general, video source 104 represents a source of video data (i.e., raw, unencoded video data) and provides a continuous series of pictures (also called "frames") of the video data to video encoder 200, which encodes the data for the 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 generate computer graphics-based data as source video, or a combination of live video, archived video, and computer-generated video. In each case, video encoder 200 encodes the captured video data, pre-captured video data, or computer-generated video data. Video encoder 200 may rearrange the pictures from the order in which they were received (sometimes called "display order") to a coding order for coding. Video encoder 200 may generate a bitstream including the encoded video data. The source device 102 may then output the encoded video data via the output interface 108 to a computer-readable medium 110 for receipt and / or retrieval, for example, by an input interface 122 of the destination device 116 .

[0032]

[0045] The memory 106 of the source device 102 and the memory 120 of the destination device 116 represent general purpose memories. In some examples, the memories 106, 120 may store raw video data, e.g., raw video from the video source 104 and raw decoded video data from the video decoder 300. Additionally or alternatively, the memories 106, 120 may store software instructions executable by, e.g., the video encoder 200 and the video decoder 300, respectively. Although the memories 106 and 120 are shown in this example separately from the video encoder 200 and the video decoder 300, it should be understood that the video encoder 200 and the video decoder 300 may also include internal memories for functionally similar or equivalent purposes. Additionally, the memories 106, 120 may store encoded video data, e.g., output from the video encoder 200 and input to the video decoder 300. In some examples, portions of the memories 106, 120 may be allocated as one or more video buffers, for example, for storing raw decoded video data and / or encoded video data.

[0033]

[0046] The computer-readable medium 110 may represent any type of medium or device capable of transferring encoded video data from the source device 102 to the destination device 116. In one example, the computer-readable medium 110 represents a communication medium for enabling the source device 102 to transmit the encoded video data directly to the destination device 116 in real time, for example, via a radio frequency network or a computer-based network. The output interface 108 may modulate a transmission signal including the encoded video data, and the input interface 122 may demodulate a received transmission signal according to a communication standard such as a wireless communication protocol. The communication medium may comprise any wireless or wired communication medium, such as a radio frequency (RF) spectrum or one or more physical transmission paths. The communication medium may form part of a packet-based network, such as a local area network, a wide area network, or a global network such as the Internet. The communication medium may include routers, switches, base stations, or any other equipment that may be useful for facilitating communication from the source device 102 to the destination device 116.

[0034]

[0047] In some examples, source device 102 may output the encoded data from output interface 108 to storage device 112. Similarly, destination device 116 may access the encoded data from storage device 112 via input interface 122. Storage device 112 may include any of a variety of distributed or locally accessed data storage media, such as a hard drive, Blu-ray disc, DVD, CD-ROM, flash memory, volatile or non-volatile memory, or any other suitable digital storage medium for storing encoded video data.

[0035]

[0048] In some examples, source device 102 may output the encoded video data to a file server 114 or another intermediate storage device, which may store the encoded video data generated by source device 102. Destination device 116 may access the stored video data from file server 114 via streaming or download.

[0036]

[0049] The file server 114 may be any type of server device capable of storing encoded video data and transmitting the encoded video data to the destination device 116. The file server 114 may represent a web server (e.g., for a website), a server configured to provide file transfer protocol services (such as File Transfer Protocol (FTP) or File Delivery over Unidirectional Transport (FLUTE) protocol), a content delivery network (CDN) device, a Hypertext Transfer Protocol (HTTP) server, a Multimedia Broadcast Multicast Service (MBMS) or Enhanced MBMS (eMBMS) server, and / or a network attached storage (NAS) device. The file server 114 may additionally or alternatively implement one or more HTTP streaming protocols, such as Dynamic Adaptive Streaming over HTTP (DASH), HTTP Live Streaming (HLS), Real Time Streaming Protocol (RTSP), HTTP Dynamic Streaming, etc.

[0037]

[0050] The destination device 116 may access the encoded video data from the file server 114 through any standard data connection, including an Internet connection. This may include a wireless channel (e.g., a Wi-Fi connection), a wired connection (e.g., a digital subscriber line (DSL), a cable modem, etc.), or a combination of both suitable for accessing the encoded video data stored on the file server 114. The input interface 122 may be configured to operate according to any one or more of the various protocols discussed above for retrieving or receiving media data from the file server 114 or other such protocols for retrieving media data.

[0038]

[0051] Output interface 108 and input interface 122 may represent wireless transmitters / receivers, modems, wired networking components (e.g., Ethernet cards), wireless communication components operating according to any of the various IEEE 802.11 standards, or other physical components. In examples in which output interface 108 and input interface 122 comprise wireless components, output interface 108 and input interface 122 may be configured to transfer data, such as encoded video data, according to a cellular communication standard, such as 4G, 4G-LTE (Long Term Evolution), LTE Advanced, 5G, etc. In some examples in which output interface 108 comprises a wireless transmitter, output interface 108 and input interface 122 may be configured to transfer data, such as encoded video data, according to other wireless standards, such as the IEEE 802.11 specification, the IEEE 802.15 specification (e.g., ZigBee™), the Bluetooth™ standard, etc. In some examples, source device 102 and / or destination device 116 may include respective system-on-a-chip (SoC) devices. For example, source device 102 may include a SoC device for performing functions attributed to video encoder 200 and / or output interface 108, and destination device 116 may include a SoC device for performing functions attributed to video decoder 300 and / or input interface 122.

[0039]

[0052] The techniques of this disclosure may be applied to video coding to support any of a variety of multimedia applications, such as over-the-air television broadcast, cable television transmission, satellite television transmission, Internet streaming video transmission such as Dynamic Adaptive Streaming over HTTP (DASH), digital video being encoded on a data storage medium, decoding of digital video stored on a data storage medium, or other applications.

[0040]

[0053] An input interface 122 of the destination device 116 receives an encoded video bitstream from a computer-readable medium 110 (e.g., a communication medium, a storage device 112, a file server 114, etc.). The encoded video bitstream may include signaling information defined by the video encoder 200 that is also used by the video decoder 300, such as syntax elements having values ​​that describe characteristics and / or processing of video blocks or other coded units (e.g., slices, pictures, groups of pictures, sequences, etc.). The display device 118 displays decoded pictures of the decoded video data to a user. The display device 118 may represent any of a variety of display devices, such as a liquid crystal display (LCD), a plasma display, an organic light emitting diode (OLED) display, or another type of display device.

[0041]

[0054] Although not shown in FIG. 1, in some examples, the video encoder 200 and the video decoder 300 may each be integrated with an audio encoder and / or audio decoder and may include appropriate MUX-DEMUX units or other hardware and / or software to handle multiplexed streams that include both audio and video in a common data stream.

[0042]

[0055] The video encoder 200 and the video decoder 300 may each be implemented as any of a variety of suitable encoder and / or decoder circuits, such as one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), discrete logic, software, hardware, firmware, or any combination thereof. When the techniques are implemented partially in software, a device may store software instructions on a suitable non-transitory computer-readable medium and execute the instructions in hardware using one or more processors to perform the techniques of this disclosure. Each of the video encoder 200 and the 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) within the respective device. The device including the video encoder 200 and / or the video decoder 300 may comprise an integrated circuit, a microprocessor, and / or a wireless communication device such as a cellular phone.

[0043]

[0056] The video encoder 200 and the 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 multiview and / or scalable video coding extensions. Alternatively, the video encoder 200 and the video decoder 300 may operate according to other proprietary or industry standards, such as ITU-T H.266, also referred to as Versatile Video Coding (VVC). In other examples, the video encoder 200 and the video decoder 300 may operate according to a proprietary video codec / format, such as AOMedia Video1 (AV1), an extension of AV1, and / or a successor version of AV1 (e.g., AV2). In other examples, the video encoder 200 and the video decoder 300 may operate according to other proprietary formats or industry standards. However, the techniques of this disclosure are not limited to any particular coding standard or format. In general, video encoder 200 and video decoder 300 may be configured to perform the techniques of this disclosure with any video coding technique that uses geometric prediction mode (GEO).

[0044]

[0057] In GEO (i.e., GPM), as described above, the current block is divided into two parts by a geometrically arranged straight edge (e.g., a straight line). The straight edge may intersect with two different edges of the current block (e.g., a line from the top edge to the bottom edge at different angles, a line from the right edge to the top edge at different angles, a line from the right edge to the bottom edge at different angles, a line from the right edge to the left edge at different angles, a line from the left edge to the top edge at different angles, and a line from the left edge to the bottom edge at different angles). Each of these exemplary lines may be considered as a partition mode of GEO. The video encoder may signal information indicating the partition mode to the video decoder.

[0045]

[0058] This disclosure describes an example method for reducing overhead associated with signaling information related to GEO. For example, as described in more detail below, index values ​​(e.g., the angle and offset of the line dividing the current block) used to identify which of the partition modes to use may be grouped and rearranged. For example, the video encoder 200 and the video decoder 300 may access from memory a mapping table (e.g., a mapping list) in which two or more GEO partition modes are grouped together (e.g., to have the same index value in the mapping table). As an example, two or more GEO modes may be grouped together based on two or more GEO partition modes having the same offset index and an angle that is approximately perpendicular to each other. The number of GEO partition modes is equal to M, and the number of partition modes in each group of the two or more GEO partition modes is equal to K, where K is less than M. Thus, there may be M / K groups. The M / K groups may be identifiable by their respective index values. In this manner, signaling overhead may be reduced because there are fewer index values ​​(e.g., M / K indexes are less than M indexes).

[0046]

[0059] Once the video encoder 200 or the video decoder 300 identifies a group by an index value (e.g., one of the groups having K partition modes), the video encoder 200 or the video decoder 300 may determine a partition mode from the K partition modes in the group. For example, each of the K partition modes may be identifiable by a respective sub-mode index value.

[0047]

[0060] In some examples, the video encoder 200 and the video decoder may reorder the K partition modes in a group based on a cost value (e.g., template matching (TM) cost) such that partition modes with lower costs are associated with lower sub-mode index values. A partition mode with a lower cost may have a higher selectability. Thus, a sub-mode index value for a partition mode with a lower cost that is smaller than a sub-mode index value for a partition mode with a higher cost may make it more likely that the video encoder 200 signals a lower index value. In general, signaling a lower index value may require less overhead than a larger index value. Thus, in one or more examples, this disclosure describes example methods for reducing the amount of signaled data and promoting efficient bandwidth.

[0048]

[0061] In the above examples, the video encoder 200 and the video decoder 300 may access a mapping table (e.g., a mapping list) with the partition modes grouped together. However, the example techniques are not so limited. In some examples, the video encoder 200 and the video decoder 300 may determine the costs (e.g., TM costs) associated with the partition modes (e.g., M partition modes), possibly, but not necessarily, prior to and without grouping. The video encoder 200 and the video decoder 300 may build the mapping table (e.g., a mapping list) based on the costs. For example, the video encoder 200 and the video decoder 300 may order the partition modes in ascending order starting with the partition mode having the lowest cost (e.g., an index value for a partition mode having the lowest cost is lower than an index value for a partition mode having a higher cost).

[0049]

[0062] The video encoder 200 and the video decoder 300 may determine the partition modes from the constructed mapping table (e.g., mapping list). In some examples, the video encoder 200 and the video decoder 300 may then be able to group the partition modes (e.g., based on GEO partition modes that have the same offset index and angles that are approximately perpendicular to each other). That is, the video encoder 200 and the video decoder 300 may first determine the cost (e.g., TM cost, but other cost values ​​are possible), construct the mapping table (e.g., mapping list), and then perform the grouping. However, as described further below, it may be possible to first group the partition modes and then determine the cost. Also, in some examples, the video encoder 200 and the video decoder 300 may determine the cost and construct the mapping list without any grouping of the partition modes.

[0050]

[0063] In general, the video encoder 200 and the video decoder 300 may perform block-based coding of pictures. The term "block" generally refers to a structure that includes data to be processed (e.g., encoded, decoded, or otherwise used in an encoding and / or decoding process). For example, a block may include a two-dimensional matrix of samples of luminance and / or chrominance data. In general, the video encoder 200 and the video decoder 300 may code video data represented in a YUV (e.g., Y, Cb, Cr) format. That is, rather than coding red, green, and blue (RGB) data for samples of a picture, the video encoder 200 and the video decoder 300 may code a luma component and a chroma component, which may include both red and blue chroma components. In some examples, the video encoder 200 converts received RGB formatted data to a YUV representation before encoding, and the video decoder 300 converts the YUV representation to an RGB format. Alternatively, pre-processing and post-processing units (not shown) may perform these conversions.

[0051]

[0064] This disclosure may generally refer to coding (e.g., encoding and decoding) a picture as including a process of encoding or decoding data for a picture. Similarly, this disclosure may refer to coding a block of a picture as including a process of encoding or decoding data for the block, such as predictive and / or residual coding. A coded video bitstream generally includes a set of values ​​for syntax elements that represent coding decisions (e.g., coding modes) and partitioning of a picture into blocks. Thus, references to coding a picture or a block should generally be understood as coding values ​​for the syntax elements that form the picture or block.

[0052]

[0065] 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 CTUs and CUs into four equal non-overlapping squares, and each node of the quadtree has either zero or four child nodes. A node without children may be called a "leaf node", and a 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 quadtree (RQT) represents a partition of TUs. In HEVC, a PU represents inter-predicted data, and a TU represents residual data. An intra-predicted CU includes intra-prediction information, such as an intra-mode indication.

[0053]

[0066] As another example, the video encoder 200 and the video decoder 300 may be configured to operate according to VVC. According to VVC, a video coder (such as the video encoder 200) partitions a picture into multiple coding tree units (CTUs). The video encoder 200 may partition the CTUs according to a tree structure, such as a quad-tree binary tree (QTBT) structure or a multi-type tree (MTT) structure. The QTBT structure eliminates the concept of multiple partition types, such as the separation between CUs, PUs, and TUs in HEVC. The QTBT structure includes two levels, a first level partitioned according to a quad-tree partition, and a second level partitioned according to a binary tree partition. The root node of the QTBT structure corresponds to a CTU. The leaf nodes of the binary tree correspond to coding units (CUs).

[0054]

[0067] In the MTT partitioning structure, blocks may be partitioned using quad tree (QT) partitioning, binary tree (BT) partitioning, and one or more types of triple tree (TT) (also called ternary tree (TT)) partitioning. A triple tree partitioning or ternary tree partitioning is a partitioning in which a block is divided into three sub-blocks. In some examples, a triple tree partitioning or ternary tree partitioning partitions a block into three sub-blocks without partitioning the original block through the center. The partition types in MTT (e.g., QT, BT, and TT) may be symmetric or asymmetric.

[0055]

[0068] When operating according to the AV1 codec, the video encoder 200 and the video decoder 300 may be configured to code video data in blocks. In AV1, the largest coding block that may be processed is called a superblock. In AV1, a superblock may be either 128×128 luma samples or 64×64 luma samples. However, in successor video coding formats (e.g., AV2), a superblock may be defined by a different (e.g., larger) luma sample size. In some examples, a superblock is the top level of a block quadtree. The video encoder 200 may further partition the superblock into smaller coding blocks. The video encoder 200 may partition the superblock and other coding blocks into smaller blocks using square or non-square partitions. The non-rectangular blocks may include N / 2×N, N×N / 2, N / 4×N, and N×N / 4 blocks. The video encoder 200 and the video decoder 300 may perform separate prediction and transformation processes for each of the coding blocks.

[0056]

[0069] AV1 also defines tiles of video data. A tile is a rectangular array of superblocks that may be coded independently of other tiles. That is, video encoder 200 and video decoder 300 may encode and decode coding blocks within a tile, respectively, without using video data from other tiles. However, video encoder 200 and video decoder 300 may perform filtering across tile boundaries. Tiles may be uniform or non-uniform in size. Tile-based coding may enable parallel processing and / or multi-threading for encoder and decoder implementations.

[0057]

[0070] In some examples, the video encoder 200 and the video decoder 300 may use a single QTBT or MTT structure to represent each of the luma and chroma components, while in other examples, the video encoder 200 and the video decoder 300 may use two or more QTBT or MTT structures, such as one QTBT / MTT structure for the luma component and another QTBT / MTT structure for both chroma components (or two QTBT / MTT structures for each chroma component).

[0058]

[0071] Video encoder 200 and video decoder 300 may be configured to use quadtree partitioning, QTBT partitioning, MTT partitioning, superblock partitioning, or other partitioning structures.

[0059]

[0072] In some examples, the CTU includes a coding tree block (CTB) of luma samples, two corresponding CTBs of chroma samples for a picture having three sample arrays, or a CTB of samples for a picture coded using three separate color planes and syntax structures used to code a monochrome picture or sample. The CTB may be an N×N block of samples for some value of N such that the partitioning of the components into the CTB is partitioned. A component is an array or a single sample from one of the three arrays (luma and two chroma) that make up a picture in 4:2:0, 4:2:2, or 4:4:4 color format, or a single sample of an array or arrays that make up 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 partitioning of the CTB into the coding block is partitioned.

[0060]

[0073] Blocks (e.g., CTUs or CUs) may be grouped in various ways within a picture. As an example, a brick may refer to a rectangular region of a CTU row within a particular tile within a picture. A tile may be a rectangular region of CTUs within a particular tile column and a particular tile row within a picture. A tile column refers to a rectangular region of CTUs with a height equal to the height of the picture and a width specified by a syntax element (e.g., in a picture parameter set). A tile row refers to a rectangular region of CTUs with a height specified by a syntax element (e.g., in a picture parameter set) and a width equal to the width of the picture.

[0061]

[0074] In some examples, a tile may be partitioned into multiple bricks, each of which may include one or more CTU rows within the tile. A tile that is not partitioned into multiple bricks may also be referred to as a brick. However, a brick that is a true subset of a tile may not be referred to as a tile. Bricks in a picture may also be arranged as slices. A slice may be an integer number of bricks of a picture that may be contained exclusively within a single Network Abstraction Layer (NAL) Unit. In some examples, a slice includes either several complete tiles or only a series of contiguous complete bricks of a tile.

[0062]

[0075] This disclosure may use "NxN" and "N by N" interchangeably to refer to the sample dimensions of a block (such as a CU or other video block) in terms of the vertical and horizontal dimensions, e.g., 16x16 samples or 16 by 16 samples. In general, a 16x16 CU has 16 samples in the vertical direction (y=16) and 16 samples in the horizontal direction (x=16). Similarly, an NxN 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 in a CU may be arranged in rows and columns. Moreover, a CU does not necessarily have to have the same number of samples in the horizontal direction as in the vertical direction. For example, a CU may comprise NxM samples, where M is not necessarily equal to N.

[0063]

[0076] Video encoder 200 encodes video data for a CU that represents prediction and / or residual information, as well as other information. The prediction information indicates how the CU will be predicted to form a predictive block for the CU. The residual information generally represents sample-by-sample differences between samples of the CU and samples of the predictive block before encoding.

[0064]

[0077] To predict a CU, the video encoder 200 may form a predictive block for the CU generally through inter prediction or intra prediction. Inter prediction generally refers to predicting a CU from data of a previously coded picture, and intra prediction generally refers to predicting a CU from previously coded data of the same picture. To implement inter prediction, the video encoder 200 may generate a predictive block using one or more motion vectors. The video encoder 200 may generally perform a motion search to identify a reference block that closely matches the CU with respect to the difference between the CU and the reference block, for example. The video encoder 200 may calculate a difference metric using a sum of absolute differences (SAD), a sum of squared differences (SSD), a mean absolute difference (MAD), a mean squared difference (MSD), or other such difference calculation to determine whether the reference block matches well with the current CU. In some examples, the video encoder 200 may predict the current CU using unidirectional prediction or bidirectional prediction.

[0065]

[0078] Some examples of VVC also provide an affine motion compensation mode, which may be considered an inter-prediction mode. In an affine motion compensation mode, video encoder 200 may determine two or more motion vectors that represent non-translational motion, such as zooming in or out, rotation, viewpoint shifting, or other irregular motion types.

[0066]

[0079] To perform intra prediction, the video encoder 200 may select an intra prediction mode to generate a prediction block. Some examples of VVC provide 67 intra prediction modes, including various orientation modes, as well as a planar mode and a DC mode. In general, the video encoder 200 selects an intra prediction mode that describes neighboring samples for a current block (e.g., a block of a CU) from which samples of the current block should be predicted. Such samples may generally be above, above and to the left, or to the left of the current block, in the same picture as the current block, assuming that the video encoder 200 codes CTUs and CUs in raster scan order (left to right, top to bottom).

[0067]

[0080] The video encoder 200 encodes data representing a prediction mode for the current block. For example, in the case of an inter prediction mode, the video encoder 200 may encode data representing which of various available inter prediction modes is used as well as motion information for the corresponding mode. In the case of unidirectional or bidirectional inter prediction, for example, the video encoder 200 may encode a motion vector using an advanced motion vector prediction (AMVP) mode or a merge mode. The video encoder 200 may use a similar mode to encode a motion vector for an affine motion compensation mode.

[0068]

[0081] AV1 includes two general techniques for encoding and decoding coding blocks of video data. The two general techniques are intra prediction (e.g., intra-frame prediction or spatial prediction) and inter prediction (e.g., inter-frame prediction or temporal prediction). In the context of AV1, when predicting a block of a current frame of video data using an intra prediction mode, the video encoder 200 and the video decoder 300 do not use video data from other frames of the video data. In most intra prediction modes, the video encoder 200 encodes a block of the current frame based on a difference between a sample value in the current block and a predicted value generated from a reference sample in the same frame. The video encoder 200 determines the predicted value generated from the reference sample based on the intra prediction mode.

[0069]

[0082] Following prediction, such as intra- or inter-prediction, of a block, the video encoder 200 may compute residual data for the block. The residual data, such as a residual block, represents sample-by-sample differences between the block and a predictive block for that block formed using a corresponding prediction mode. The video encoder 200 may apply one or more transforms to the residual block to generate transform data in a transform domain rather than the sample domain. For example, the video encoder 200 may apply a discrete cosine transform (DCT), an integer transform, a wavelet transform, or a conceptually similar transform to the residual video data. In addition, the video encoder 200 may apply a secondary transform, such as a mode-dependent non-separable secondary transform (MDNSST), a signal-dependent transform, a Karhunen-Loeve transform (KLT), etc., following the initial transform. The video encoder 200 generates transform coefficients following application of the one or more transforms.

[0070]

[0083] As mentioned above, following any transformation to generate transform coefficients, the video encoder 200 may perform quantization of the transform coefficients. Quantization generally refers to a process in which transform coefficients are quantized to possibly reduce the amount of data used to represent the transform coefficients, providing further compression. By performing a quantization process, the video encoder 200 may reduce the bit depth associated with some or all of the transform coefficients. For example, the 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, the video encoder 200 may perform a bitwise right shift of the value to be quantized.

[0071]

[0084] Following quantization, the video encoder 200 may scan the transform coefficients to generate a one-dimensional vector from the two-dimensional matrix including the quantized transform coefficients. The scan may be designed to place transform coefficients with higher energy (and therefore lower frequency) at the front of the vector and transform coefficients with lower energy (and therefore higher frequency) at the rear of the vector. In some examples, the video encoder 200 may use a predefined scan order for scanning the quantized transform coefficients to generate a serialized vector and then entropy code the quantized transform coefficients of the vector. In other examples, the video encoder 200 may perform an adaptive scan. After scanning the quantized transform coefficients to form the one-dimensional vector, the video encoder 200 may entropy code the one-dimensional vector, for example, according to context-adaptive binary arithmetic coding (CABAC). The video encoder 200 may also entropy code values ​​for syntax elements that describe metadata associated with the encoded video data for use by the video decoder 300 in decoding the video data.

[0072]

[0085] To perform CABAC, the video encoder 200 may assign a context in a context model to a symbol to be transmitted. The context may relate, for example, to whether neighboring values ​​of the symbol are zeroed out or not. The probability decision may be based on the context assigned to the symbol.

[0073]

[0086] Video encoder 200 may further generate syntax data, such as block-based syntax data, picture-based syntax data, and sequence-based syntax data, for example in a picture header, block header, slice header, or other syntax data, such as a sequence parameter set (SPS), a picture parameter set (PPS), or a video parameter set (VPS), to video decoder 300. Video decoder 300 may similarly decode such syntax data to determine how to decode the corresponding video data.

[0074]

[0087] In this manner, video encoder 200 may generate a bitstream including encoded video data, e.g., syntax elements that describe partitions of a picture into blocks (e.g., CUs) and prediction and / or residual information for the blocks. Finally, video decoder 300 may receive the bitstream and may decode the encoded video data.

[0075]

[0088] In general, video decoder 300 performs a reciprocal process to that performed by video encoder 200 to decode encoded video data of a bitstream. For example, video decoder 300 may decode values ​​for syntax elements of a bitstream using CABAC in a manner substantially similar to, but reciprocal to, the CABAC encoding process of video encoder 200. The syntax elements may specify partition information for the partitioning of a picture into CTUs and the partitioning of each CTU according to a corresponding partitioning structure, such as a QTBT structure, to specify CUs of the CTU. The syntax elements may further specify prediction and residual information for blocks of video data (e.g., CUs).

[0076]

[0089] The residual information may be represented, for example, by quantized transform coefficients. The video decoder 300 may dequantize and inverse transform the quantized transform coefficients of the block to reconstruct a residual block for the block. The video decoder 300 may use the signaled prediction mode (intra-prediction or inter-prediction) and associated prediction information (e.g., motion information for inter-prediction) to form a predictive block for the block. The video decoder 300 may then combine (sample by sample) the predictive block and the residual block to reconstruct the original block. The video decoder 300 may perform additional processing, such as performing a deblocking process to reduce visual artifacts along block boundaries.

[0077]

[0090] This disclosure may generally refer to "signaling" some information, such as a syntax element. The term "signaling" may generally refer to communication of values ​​for syntax elements and / or other data used to decode encoded video data. That is, video encoder 200 may signal values ​​for syntax elements in a bitstream. In general, signaling refers to generating values ​​within the bitstream. As discussed above, source device 102 may transport the bitstream to destination device 116 in substantially real-time or non-real-time, such as occurs when storing syntax elements in storage device 112 for later retrieval by destination device 116.

[0078]

[0091] According to the techniques of this disclosure, the video decoder 300 may be configured to access from a memory a mapping table (e.g., a mapping list) in which two or more geometric partitioning mode (GEO) partition modes are grouped together such that they have the same index value in the mapping table, where the number of GEO partition modes is equal to M and the number of partition modes in each group of two or more GEO partition modes is equal to K, where K is less than M. In some examples, M is non-zero. Although K may be non-zero, it is also possible for K to be zero. The video decoder 300 may be configured to determine one partition mode of the multiple partition modes from the mapping table and reconstruct a current block of video data based on the partition mode (e.g., the determined partition mode).

[0079]

[0092] In one example, video encoder 200 may be configured to access from memory a mapping table (e.g., a mapping list) in which two or more geometric partition mode (GEO) partition modes are grouped together such that they have the same index value in the mapping table, where the number of GEO partition modes is equal to M and the number of partition modes in each group of two or more GEO partition modes is equal to K, where K is less than M. Video encoder 200 may be configured to determine the partition mode from the mapping table and signal an index value into the mapping table that indicates the partition mode for decoding a current block of video data.

[0080]

[0093] In one example, the video decoder 300 may be configured to determine respective costs (e.g., TM costs) associated with one or more partition modes of a geometric partitioning mode (GEO), construct a mapping table (e.g., a mapping list) having values ​​indicating the respective partition modes based on the respective costs for the one or more partition modes of the GEO, determine one partition mode among the multiple partition modes based on the mapping table (e.g., the mapping list), and reconstruct a current block of video data based on the partition mode (e.g., the determined partition mode).

[0081]

[0094] In one example, video encoder 200 may be configured to determine respective costs associated with one or more partition modes of a geometric partitioning mode (GEO), build a mapping table (e.g., a mapping list) having values ​​indicative of the respective partition modes based on the respective costs for the one or more partition modes of GEO, determine one partition mode among the multiple partition modes based on the mapping table, and signal an index (e.g., an index value) to the mapping table indicating the partition mode for decoding a current block of video data.

[0082]

[0095] The following provides some background related to video coding standards and different prediction modes: Video coding standards include ITU-T H.261, ISO / IEC MPEG-1 Visual, ITU-T H.262 or ISO / IEC MPEG-2 Visual, ITU-T H.263, ISO / IEC MPEG-4 Visual, and ITU-T H.264 (also called ISO / IEC MPEG-4 AVC), including their Scalable Video Coding (SVC) and Multiview Video Coding (MVC) extensions.

[0083]

[0096] Additionally, High Efficiency Video Coding (HEVC) or ITU-T H.265, including its range extensions, multiview extensions (MV-HEVC), and scalable extensions (SHVC), have been developed by the Joint Collaboration Team on Video Coding (JCT-VC) and the Joint Collaboration Team on 3D Video Coding Extension Development (JCT-3V) of the ITU-T Video Coding Experts Group (VCEG) and the ISO / IEC Motion Picture Experts Group (MPEG).

[0084]

[0097] The latest HEVC draft specification, hereafter referred to as HEVC WD, is available at http: / / phenix.int-evry.fr / jct / doc_end_user / documents / 14_Vienna / wg11 / JCTVC-N1003-v1.zip.

[0085]

[0098] ITU-T VCEG (Q6 / 16) and ISO / IEC MPEG (JTC 1 / SC 29 / WG 11) are working together in a joint collaboration effort known as JVET (Joint Video Exploration Team) to evaluate compression technology designs proposed by their experts in this field. The latest version of the reference software, i.e., VVC Test Model 10 (VTM10), can be downloaded from https: / / vcgit.hhi.fraunhofer.de / jvet / VVCSoftware_VTM. The Versatile Video Coding (VVC) draft standard can be found in JVET-T2001, "Versatile Video Coding Editorial Refinations on Draft 10," by Bross et al., JVET, ITU-T SG 16 WP3, and the 20th meeting of ISO / IEC JTC 1 / SC 29, by videoconference (7-16 October 2020). The algorithmic description of the Generic Video Coding and Test Model 10 (VTM10.0) is sometimes referred to as JVET-T2002.

[0086]

[0099] In HEVC, the largest coding unit in a slice is called a coding tree block (CTB) or coding tree unit (CTU). The CTB contains a quadtree, and the nodes of the quadtree are coding units.

[0087]

[0100] The size of the CTB can range from 16x16 to 64x64 in HEVC Main Profile (although technically a CTB size of 8x8 can be supported). Coding units (CUs) can be as small as 8x8 to the same size of the CTB. Each coding unit is coded using one mode, namely inter-mode or intra-mode. A CU may be further partitioned into 2 or 4 prediction units (PUs) when inter-coded, or just one PU when no further partitioning applies. When there are two PUs in one CU, the PUs may be a rectangle with half the size of the CU, or two rectangles with 1 / 4 or 3 / 4 the size of the CU.

[0088]

[0101] When a CU is inter-coded, each PU has one set of motion information, which is derived using a unique inter-prediction mode. In the HEVC standard, there are two inter-prediction modes for a prediction unit (PU), named merge mode (skip is considered to be a special case of merge) and advanced motion vector prediction (AMVP) mode, respectively.

[0089]

[0102] In either AMVP mode or merge mode, a motion vector (MV) candidate list is maintained for multiple motion vector predictors. The motion vector(s) of the current PU and the reference index in merge mode are generated by taking one candidate from the MV candidate list.

[0090]

[0103] The MV candidate list contains up to five candidates for merge mode and only two candidates for AMVP mode. A merge candidate may contain a set of motion information, e.g., a motion vector corresponding to both the reference picture list (list 0 and list 1) and a reference index. If a merge candidate is identified by a merge index, the reference picture and associated motion vector used for prediction of the current block are determined. On the other hand, under AMVP mode, for each possible prediction direction from either list 0 or list 1, a reference index needs to be explicitly signaled along with the MV predictor (MVP) index to the MV candidate list, since the AMVP candidate contains only a motion vector. In AMVP mode, the predicted motion vector can be further improved.

[0091]

[0104] Candidates for both modes are derived identically from the same spatial and temporal neighboring blocks.

[0092]

[0105] The spatial MV candidates are 0 ), are derived from the neighboring blocks shown in Figures 4A and 4B, but the method of generating candidates from the blocks is different for merge mode and AMVP mode. For example, Figure 4A shows PU0 400A and PU1 400B, and neighboring blocks for PU0 400A. Figure 4B shows PU0 400C and PU1 400D, and neighboring blocks for PU0 400C.

[0093]

[0106] In merge mode, up to four spatial MV candidates can be derived with the order shown in FIG. 4A using numbers as follows: left (0, A1), top (1, B1), top right (2, B0), bottom left (3, A0), and top left (4, B2) as shown in FIG. 4A.

[0094]

[0107] Figure 4B shows the order for AMVP mode. As shown in Figure 4B, in AMVP mode, neighboring blocks are divided into two groups: a left group consisting of blocks 0 and 1, and an upper group consisting of blocks 2, 3, and 4. For each group, the possible candidates among the neighboring blocks that refer to the same reference picture as indicated by the signaled reference index have the highest priority to be chosen to form the final candidate of the group. It may be that all neighboring blocks do not contain motion vectors that point to the same reference picture. Therefore, if such a candidate cannot be found, the first available candidate will be scaled to form the final candidate. Thus, the temporal distance difference can be compensated.

[0095]

[0108] Temporal motion vector predictor (TMVP) candidates, if enabled and available, are added into the MV candidate list after spatial motion vector candidates. The process of motion vector derivation for TMVP candidates is the same for both merge mode and AMVP mode, but the target reference index for TMVP candidates in merge mode is always set to 0.

[0096]

[0109] The primary block location for TMVP candidate derivation is the outer bottom-right block of the co-located PU, as shown in Figure 5A as block "T" (i.e., block 500), to compensate for the bias towards the blocks above and to the left used to generate spatially neighboring candidates. However, if the block is located outside the current CTB row or motion information is not available (e.g., as shown in block 502 with a cross), the block is replaced with the center block of the PU, shown as block 504.

[0097]

[0110] The motion vectors for TMVP candidates are derived from the co-located PUs of the co-located pictures, which are shown at the slice level. The motion vectors for the co-located PUs are called co-located MVs. Similar to the temporal direct mode in AVC, to derive the TMVP candidate motion vectors, the co-located MVs may need to be scaled to compensate for the temporal distance difference, as shown in Figure 5B.

[0098]

[0111] In the following, some other aspects of motion prediction in HEVC are described. Some aspects of merge mode and AMVP mode are worth mentioning as follows:

[0099]

[0112] Motion Vector Scaling: It is assumed that the value of a motion vector is proportional to the distance of pictures in presentation time. A motion vector relates two pictures, namely a reference picture and the picture that contains the motion vector (i.e., the stored picture). When a motion vector is used to predict another motion vector, the distance between the stored picture and the reference picture is calculated based on the Picture Order Count (POC) value.

[0100]

[0113] For a motion vector to be predicted, both its associated stored picture and reference picture may be different. Therefore, a new distance (based on POC) is calculated, and the motion vector is scaled based on these two POC distances. For spatial neighbor candidates, the stored pictures for the two motion vectors are the same, but the reference pictures are different. In HEVC, the motion vector scaling is applied to both TMVP and AMVP for spatial and temporal neighbor candidates.

[0101]

[0114] Artificial motion vector candidate generation: If the motion vector candidate list is not complete, an artificial motion vector candidate is generated and inserted at the end of the list until the list has all the candidates. In merge mode, there are two types of artificial MV candidates: a combined candidate that is derived only for B slices, and a zero candidate that is used only for AMVP when the first type does not provide enough artificial candidates.

[0102]

[0115] For each pair of candidates already in the candidate list and having the necessary motion information, a bidirectional composite motion vector candidate is derived by combining the motion vector of the first candidate that references a picture in list 0 and the motion vector of the second candidate that references a picture in list 1.

[0103]

[0116] Pruning process for candidate insertion: Candidates from different blocks may happen to be the same, which reduces the efficiency of the merge / AMVP candidate list. To solve this problem, a pruning process is applied. The pruning process involves comparing a candidate with other candidates in the current candidate list to some extent to avoid inserting the same candidate. To reduce the complexity, instead of comparing each possible candidate with all other existing candidates, the pruning process is applied only a limited number of times.

[0104]

[0117] Reference picture resampling is described below. In HEVC, the spatial resolution of a picture cannot be changed unless a new sequence using a new SPS starts with an IRAP picture. VVC allows picture resolution change at a position in a sequence without encoding an IRAP picture, which is always intra-coded. This feature is sometimes called reference picture resampling (RPR) because it requires resampling of reference pictures used for inter prediction when the reference picture has a different resolution than the current picture being decoded. To avoid additional processing steps, the RPR process in VVC is designed to be incorporated into the motion compensation process and performed at the block level. In the motion compensation stage, the scaling ratio is used together with the motion information to identify the location of reference samples in the reference picture used in the interpolation process.

[0105]

[0118] In VVC, the scaling ratio is limited to be greater than or equal to 1 / 2 (2x downsampling from reference picture to current picture) and less than or equal to 8 (8x upsampling). Three sets of resampling filters with different frequency cutoffs are specified to handle various scaling ratios between the reference picture and the current picture. The three sets of resampling filters are applied for scaling ratios ranging from 1 / 2 to 1 / 1.75, 1 / 1.75 to 1 / 1.25, and 1 / 1.25 to 8, respectively. Each set of resampling filters has 16 phases for luma and 32 phases for chroma, which is the same as for the motion compensated interpolation filters. The filter set of normal motion compensated (MC) interpolation may be used for scaling ratios ranging from 1 / 1.25 to 8. The normal MC interpolation process may be considered as a special case of the resampling process with scaling ratios ranging from 1 / 1.25 to 8. In addition to the conventional translational block motion, the affine mode has three sets of 6-tap interpolation filters used for the luma component to cover different scaling ratios in RPR. The horizontal and vertical scaling ratios are derived based on the picture width and height, and the left, right, top, and bottom scaling offsets specified for the reference and current pictures.

[0106]

[0119] To support this feature, the picture resolution and the corresponding adaptation window are signaled in the PPS (Picture Parameter Set) instead of the SPS (Sequence Parameter Set), where the maximum picture resolution is signaled.

[0107]

[0120] In the following, the geometric partitioning mode (GEO), also called GPM, is described. In VVC, the geometric partitioning mode is supported for inter prediction. When this mode is used, a CU is divided into two parts by a geometrically arranged straight line (e.g., a straight edge) shown in FIG.

[0108]

[0121] For example, FIG. 6 illustrates partition modes 600A-600N. Each of the partition modes 600A-600N defines an edge (e.g., a straight line) that partitions the current block. For example, FIG. 6 illustrates edge 602A, also referred to as straight line 602A, for partition mode 600A, and edge 602N, also referred to as straight line 602N, for partition mode 600N. Edge 602A of partition mode 600A is one exemplary way to partition the current block into two partitions; similarly, edge 602N of partition mode 600B is another exemplary way to partition the current block into two partitions.

[0109]

[0122] In the example of FIG. 6, there are two lines parallel to edge 602A, two lines parallel to edge 602N, and another edge. In one or more examples, the two lines parallel to each edge form an area where samples from the reference blocks are blended together (e.g., average weighted) to form a prediction block. For example, for each partition, there may be a motion vector that identifies a reference block. If there are two partitions, there may be two reference blocks. To generate a prediction block, the video encoder 200 and the video decoder 300 may utilize samples from the two reference blocks. To generate a sample of the prediction block that corresponds to a position within the two lines that are parallel to one edge, the video encoder 200 and the video decoder 300 may blend samples from the two reference blocks. For a sample of the prediction block that corresponds to a position outside the two lines that are parallel to one edge, the video encoder 200 and the video decoder 300 may utilize a sample of one of the two reference blocks to form a prediction block.

[0110]

[0123] In one or more examples, video encoder 200 may determine a motion vector for each of the two partitions (e.g., a first motion vector for the first partition and a second motion vector for the second partition). Video encoder 200 may signal information indicating the motion vectors that video decoder 300 receives. Video encoder 200 and video decoder 300 may determine a first reference block based on the first motion vector and determine a second reference block based on the second motion vector. Also, they may combine samples from the first reference block and samples from the second reference block to generate a predictive block for the current block.

[0111]

[0124] To combine samples from the first reference block and samples from the second reference block, the video encoder 200 and the video decoder 300 may perform weighted blending. For example, assume that the partition mode 600A is used. For samples that are relatively far from the edge 602A, the video encoder 200 and the video decoder 300 may use corresponding samples from one of the first reference block or the second reference block without blending to generate corresponding prediction samples in the prediction block. For samples that are relatively close to the edge 602A, the video encoder 200 and the video decoder 300 may weight average samples from the first reference block and the second reference block to generate corresponding prediction samples in the prediction block. The region "relatively close" to the edge 602A may be defined by the region between two lines parallel to the edge 602A. The video encoder 200 and the video decoder 300 may perform similar operations to generate prediction blocks for other partition mode examples.

[0112]

[0125] The location of the dividing line (e.g., dividing edge) is mathematically derived from the angle and offset parameters of a particular partition. In VVC, there are 64 partition modes, which can be organized first by angle (smaller to larger) and second by offset (smaller to larger), and each angle-offset setting is assigned a binarized value (i.e., 0 to 63) using a fixed-length code with each bin bypass coded. The fixed-length code is a full tree structure with 6 bins at each tree leaf node. The table below shows how the partition mode values ​​are mapped to angle-offsets, where the Nth angle mode (i.e., N=0, , 7 or 16, , 23) physically has an edge perpendicular to the edge of the (N+8)th angle mode. Each part of a geometric partition within a CU is inter-predicted using its own motion. Only uni-prediction is allowed per partition, i.e., each part has one motion vector and one reference index.

[0113]

[0126] In Table 1 below, the horizontal axis is the angle, and the vertical axis is the offset.

[0114] [Table 1]

[0115]

[0127] For example, video encoder 200 and video decoder 300 may store Table 1. Video encoder 200 may signal a value (e.g., 13). In this example, video decoder 300 may receive a value of 13 and determine, based on Table 1, that a split mode value of 13 maps to an angle of 4 and an offset of 3. As another example, a split mode value of 38 maps to an angle of 18 and an offset of 1, as shown by Table 1. An "x" in Table 1 means that such an edge is not supported.

[0116]

[0128] The uni-predictive candidate list for GEO mode is derived directly from the regular merge candidate list. We denote n as the index of the uni-predictive motion in the geometric uni-predictive candidate list. The LX motion vector of the nth merge candidate, where X is equal to the parity (even or odd) of n, is used as the nth uni-predictive motion vector for the geometric partition mode. These motion vectors are marked with "x" in the table below. If there is no corresponding LX motion vector of the nth extended merge candidate, the L(1-X) motion vector of the same candidate is used instead as the uni-predictive motion vector for the geometric partition mode.

[0117] [Table 2]

[0118]

[0129] As specified in the VVC specification (JVET-T2001), the derivation process of the GEO weights is specified in subclause 8.5.7.2 (Weighted Sample Prediction Process for Geometric Partitioning Mode). The inputs to this process are: - two variables nCbW and nCbH that specify the width and height of the current coding block, - two (nCbW) x (nCbH) arrays, predSamplesLA and predSamplesLB; - a variable angleIdx that specifies the angle index of the geometric division; a variable distanceIdx that specifies the distance index of the geometric division; - A variable cIdx that specifies the color component index. The output of this process is pbSamples, a (nCbW) by (nCbH) array of predicted sample values. The variables nW, nH, shift1, offset1, displacementX, displacementY, partFlip, and shiftHor are derived as follows: nW=(cIdx==0)?nCbW:nCbW *SubWidthC (990) nH=(cIdx==0)?nCbH:nCbH * SubHeightC (991) shift1=Max(5,17-BitDepth) (992) offset1=1<<(shift1-1) (993) displacementX=angleIdx (994) displacementY=(angleIdx+8)% 32 (995) partFlip=(angleIdx>=13 && angleIdx<=27)?0:1 (996) shiftHor=(angleIdx % 16==8||(angleIdx % 16!=0 && nH>=nW))?0:1 (997) The variables offsetX and offsetY are derived as follows: - If shiftHor is equal to 0, the following applies: offsetX=(-nW)>>1 (998) offsetY=((-nH)>>1)+ (angleIdx<16?(distanceIdx * nH)>>3:-((distanceIdx * nH)>>3)) (999) - Otherwise (shiftHor is equal to 1), the following applies: offsetX=((-nW)>>1)+ (angleIdx<16?(distanceIdx * nW)>>3:-((distanceIdx * nW)>>3)) (1000) offsetY=(-nH)>>1 (1001) The predicted samples pbSamples[x][y], where x=0..nCbW-1 and y=0..nCbH-1, are derived as follows: The variables xL and yL are derived as follows: xL=(cIdx==0)?x:x* SubWidthC (1002) yL=(cIdx==0)?y:y * SubHeightC (1003) The variable wValue specifying the weights of the prediction samples is derived based on the array disLut specified in Table 37 as follows: weightIdx=(((xL+offsetX)<<1)+1) * disLut[displacementX]+ (((yL+offsetY)<<1)+1) * disLut[displacementY] (1004) weightIdxL=partFlip?32+weightIdx:32-weightIdx (1005) wValue=Clip3(0,8,(weightIdxL+4)>>3) (1006) The predicted sample values ​​are derived as follows: pbSamples[x][y]=Clip3(0,(1< <BitDepth)-1,(predSamplesLA[x][y] * wValue+ (1007) predSamplesLB[x][y] * (8-wValue)+offset1)>>shift1)

[0119] [Table 3]

[0120]

[0130] In the following, we describe adaptive reordering of merge candidates (ARMC). In ECM, merge candidates are adaptively reordered using TM. The reordering method is applied to the regular merge candidate list, the TM merge candidate list, and the affine merge candidate list (sub-block merge candidate list excluding SbTMVP candidates). For TM merge mode, merge candidates are reordered before the TM refinement process.

[0121]

[0131] After the merge candidate list is constructed, the merge candidates are divided into several subgroups. The subgroup size is set to 5 for regular and TM merge modes. The subgroup size is set to 3 for affine merge mode. The merge candidates in each subgroup are sorted in ascending order according to their TM-based cost values. For simplicity, the merge candidates in the last but not the first subgroup are not sorted.

[0122]

[0132] The TM cost of a merge candidate is measured by the sum of absolute differences (SAD) between the template samples of the current block and their corresponding reference samples. The template comprises a set of reconstructed samples that neighbor the current block. The template's reference samples are positioned by the motion information of the merge candidate.

[0123]

[0133] When a merge candidate utilizes bi-directional prediction, the reference samples of the merge candidate's template are also generated by bi-directional prediction, as shown in Figure 7. For example, Figure 7 shows a current picture having a current block 702 and a template 703 that includes samples above and to the left of the current block 702. A first motion vector points to reference block 704, which defines a first reference template 708 that includes samples above and to the left of reference block 704. A second motion vector points to reference block 706, which defines a second reference template 710 that includes samples above and to the left of reference block 706.

[0124]

[0134] For a subblock-based merging candidate with a subblock size equal to W×H, the top template comprises several subtemplates with a size of W×1, and the left template comprises several subtemplates with a size of 1×H. As shown in Fig. 8, the motion information of the subblocks in the first row and first column of the current block is used to derive the reference samples of each subtemplate.

[0125]

[0135] For example, in Figure 8, the collocated block may be reference block 704 or 706 in Figure 7. Reference template 708 or 710 in Figure 7 may include samples above and to the left of reference block 704 or 706, as shown in Figure 8.

[0126]

[0136] Template matching prediction is described below. Template matching (TM) is a decoder-side MV derivation method for improving the motion information of a current CU by finding the closest match between a template in a current picture (i.e., the neighboring blocks above and / or to the left of the current CU) and a block in a reference picture (i.e., the same size as the template).

[0127]

[0137] As shown in Fig. 9, a better MV should be searched around the initial motion of the current CU 900 within the [-8, +8] pel search range. With the AMVP candidate selected based on the initial matching error, the MVP is refined by template matching. With the merge candidate indicated by the signaled merge index, the merged MVs corresponding to L0 and L1 are refined by template matching independently, and the less accurate candidate is further refined again using the better candidate as the prior.

[0128]

[0138] Cost function: When the motion vector points to a fractional sample position, motion compensated interpolation is required. To reduce the complexity, bilinear interpolation is used instead of the usual 8-tap DCT-IF interpolation for both template matching to generate the template on the reference picture. The matching cost C of template matching is calculated as follows: C=SAD+w * (|MVx-MV s x|+|MVy-MV s y|)

[0129]

[0139] where w is a weighting factor that can be set to an integer such as 0, 1, 2, 3, or 4, and the MV and multiple MVss denote the currently tested MV and the initial MV (e.g., the MVP candidate in AMVP mode, or the merged motion in merge mode), respectively. The SAD is used as the matching cost for template matching.

[0130]

[0140] When TM is used, motion is improved by using only luma samples. The derived motion can be used for both luma and chroma for MC inter prediction. After the MV is determined, the final MC is performed using an 8-tap interpolation filter for luma and a 4-tap interpolation filter for chroma.

[0131]

[0141] Search method: MV refinement is a pattern-based MV search using a criterion of template matching cost and a hierarchical structure. Two search patterns are supported for MV refinement: diamond search and cross search. The hierarchical structure specifies an iterative process for refining the MV, starting at a coarse MVD precision (e.g., 1 / 4-pel) and ending at a fine precision (e.g., 1 / 8-pel). The MV is directly searched at quarter luma sample MVD precision using the diamond pattern, followed by quarter luma sample MVD precision using the cross pattern, and then eighth luma sample MVD refinement using the cross pattern. The search range of MV refinement is set equal to (-8, +8) luma samples around the initial MV. When the current block is bi-predictive, both MVs are improved independently, and then the best one of them (in terms of matching cost) is set as the priority for further improving the other MV using the BCW weight value.

[0132]

[0142] In particular, JVET-J0021: Chen et al. "Description of SDR, HDR and 360 ovideo coding technology proposed by Qualcomm and Techincolor-low and high complexity versions,” JVET of ITU-T SG 16 WP 3 and ISO / IEC JTC 1 / SC 29 / WG 11 10 th meeting:San Diego,US 10-20 Apr.2018 and JVET-U0100:Chang et al “Compression efficiency methods beyond VVC,” JVET of ITU-T SG 16 WP 3 and ISO / IEC JTC 1 / SC 29,21 st The template matching proposed at the meeting,by teleconference,6-15 Jan.2021, is applied to AMVP mode and merge mode.

[0133]

[0143] As an example, the current template 902 includes a first portion 902A of samples above the current CU 900 and a second portion 902B of samples to the left of the current CU 900. The reference template 904 includes a first portion 904A and a second portion 904B of samples. For example, the initial MV of the current CU 900 may be considered to point to a reference block. The first portion 904A may be samples above the reference block. The second portion 904B may be samples to the left of the reference block.

[0134]

[0144] The video encoder 200 and the video decoder 300 may compare the current template 902 and the reference template 904 (e.g., determine the SAD) as a first cost for the initial MV. The video encoder 200 and the video decoder 300 may repeat such operations for different MVs for the current CU 900 and determine respective costs for each MV. In some examples, the MV that results in the lowest cost may be considered as the MV for the current CU 900.

[0135]

[0145] The regular merge candidate list is constructed from the following candidate order: a. Spatial MVP from spatially adjacent CUs: The first four available candidates are selected in the following order: top neighboring CU (A), left neighboring CU (L), top-right neighboring CU (AR), bottom-left neighboring CU (LB), top-left neighboring CU (LA). b. Temporal MVP from collocated CU: Only one candidate is added. c. History-based MVP: The motion information of previously coded blocks is stored in a table and used as the MVP for the current CU. d. Pairwise Average MVP: Pairwise average candidates are generated by averaging predefined pairs of candidates in the existing regular merge candidate list. e.Zero MV.

[0136]

[0146] When TM is applied in merge mode, a separate TM merge candidate list is constructed by refining the MVP of regular merge candidates based on template matching.

[0137]

[0147] In the following, Golomb-Rice coding is described. Golomb-Rice coding is a variable length coding method, which is formed by a shortened unary coded prefix code and a fixed length coded suffix code. The length of each of the prefix code and the suffix code is controlled by a parameter, the coded divisor D, where D is a positive power of 2 (e.g., 1, 2, 4, 8, ...) and is not greater than the total number of symbols to be coded.

[0138]

[0148] When there are N different symbols to be coded by using a Golomb-Rice code with divisor D, the indices of these N different symbols are decomposed into N / D groups, each group having D symbols. The group indices (e.g., 0, 1, 2, 3, ..., N / D-1) are coded by using a shortened unary code, which is the prefix code mentioned above. The indices of the D symbols in the group (e.g., 0, 1, 2, 3, ..., D-1) are then coded by using a shortened binary code (when D is not a power of 2) or a fixed-length binary code (when D is a power of 2), which is the suffix code mentioned above.

[0139]

[0149] Techniques related to GEO (i.e., GPM) may have some problems. For example, a fixed-length coding structure for GEO partition mode that treats each partition mode as equally probable may not be optimal with respect to codewords, even if it is not. This may be because such techniques do not consider information that may be inferred from causal neighboring pixels (e.g., pixels in neighboring reference pictures) to predict the edge direction (e.g., partition mode) of the current block. Thus, current syntax designs for GEO partition mode may not be optimal. This disclosure describes example techniques for improving syntax designs for GEO partition mode that may promote efficient bandwidth utilization and reduce signaling overhead and complexity.

[0140]

[0150] In the following, for ease of explanation, unless otherwise specified, a referenced cost (e.g., TM cost) may refer to an ARMC TM cost (with an N-line template design associated with a MV before MV refinement) or a template matching cost (with an N-line template design associated with a MV after MV refinement), where N may be 1, 2, 3, or more.

[0141]

[0151] Below, syntax permutations for GEO split modes using grouping are described. For example, grouping methods for GEO split modes are described first. In one example, two GEO split modes can be grouped together if they have the same offset index and their angles are nearly perpendicular to each other. For example, the paired modes are the nth split mode and the n+18th split mode when n≦35, and the nth split mode and the n+14th split mode when n>35. The following table reproduces Table 1 from above. In some examples, Table 1 shows how the angle-offset is mapped to the split mode index.

[0142] [Table 4]

[0143]

[0152] The above mapping table can be constructed as follows for forward and backward mapping between new and original split mode indexes. As can be seen, there are a total of 32 new split mode indexes. For example, (angle index 0, offset index 1) shares the sample split mode index as (angle index 8, offset index 1). That is, in the following, a value of 0 is mapped to split mode 0 or split mode 18, and in Table 1, split mode 0 is mapped to angle 0, offset 1, and split mode 18 is mapped to angle 8, offset 1.

[0144] [Table 5]

[0145]

[0153] In another example, as a simplified mapping function for the above example, the nth split mode is grouped with the (n+1)th mode for n ∈ {0, 2, 4, . . . , M-2}, where M is the total number of original GEO split modes (e.g., 64 for VVC). The new split mode index assigned to the nth and (n+1)th split modes is n / 2. In total, there are 32 new split mode indexes.

[0146]

[0154] In another example, for the simplified mapping function above, the nth split mode is grouped with the (n+M / 2)th mode for n∈{0, 1, 2, 3, ,{M / 2}-1}, where M is the total number of original GEO split modes (e.g., 64 for VVC). The new split mode index assigned to the nth and (n+M / 2)th split modes is n. In total, there are 32 new split mode indexes.

[0147]

[0155] In another example, four GEO split modes can be grouped together to further reduce the number of new split mode indexes from 32 to 16. The table below shows the forward and reverse mapping between the new split mode indexes and the original split mode indexes. In total, there are 16 new split mode indexes.

[0148] [Table 6]

[0149]

[0156] In another example, as a simplified mapping function for the above example, the nth, (n+1)th, (n+2)th, and (n+3)th split modes are grouped together for n ∈ {0, 4, 8, . . . , M-4}, where M is the total number of original GEO split modes (e.g., 64 for VVC). The new split mode index assigned to the nth, (n+1)th, (n+2)th, and (n+3)th split modes is n / 4. In total, there are 16 new split mode indexes.

[0150]

[0157] In another example, as a simplified mapping function for the above example, the nth, (n+M / 4), (n+2M / 4), and (n+3M / 4)th split modes are grouped together for n∈{0, 1, 2, 3, . . . , (M / 4)-1}, where M is the total number of original GEO split modes (e.g., 64 for VVC). The new split mode index assigned to the nth, (n+M / 4), (n+2M / 4), and (n+3M / 4)th split modes is n. In total, there are 16 new split mode indexes.

[0151]

[0158] In another example, as a generalized simplification for the mapping function, all K split modes may be grouped together, where K is a positive power of two (e.g., 2, 4, 8, 16, . . .). Specifically, the nth, (n+1), . . ., and (n+K-1)th split modes are grouped together for n ∈ {0, K, 2K, 3K, . . ., MK}, where M is the total number of original GEO split modes (e.g., 64 for VVC). The new split mode indexes assigned to the nth, (n+1), . . ., and (n+K-1)th split modes are n / K. In total, there are M / K new split mode indexes. Note that in general, K is no greater than M.

[0152]

[0159] In another example, as another generalized simplification for the mapping function, the nth, (n+M / K)th, (n+2M / K)th, (n+3M / K)th, ..., and (n+(K-1)M / K)th split modes are grouped together for n ∈ {0, 1, 2, 3, ..., (M / K)-1}, where M is the total number of original GEO split modes (e.g., 64 for VVC) and K is a positive power of two (e.g., 2, 4, 8, 16, ...). The new split mode index assigned to the nth, (n+M / K)th, (n+2M / K)th, (n+3M / K)th, ..., (n+(K-1)M / K)th split modes is n. In total, there are M / K new split mode indexes. Note that in general, K is not greater than M.

[0153]

[0160] The grouping index signature method and partition mode derivation are described below. After the grouping process as described above is performed using the grouping method for GEO partition mode, there are K partition modes that are grouped together (where each group is assigned a new partition mode index as described above in the grouping method for GEO partition mode), and there are M / K groups thus formed, where M is the total number of original GEO partition modes (e.g., 64 in VVC), K is a positive power of 2 (e.g., 2, 4, 8, 16,...), and K≦M. For example, each group contains K partition modes, and there are a total of M partition modes.

[0154]

[0161] The following examples explain various ways to indicate the value of M / K, and also explain which partition mode among the K modes is selected as the partition mode of the coding block. To avoid confusion, this disclosure hereafter refers to the new partition mode index as a group index.

[0155]

[0162] In one example, the group indices (e.g., 0, 1, . . . , M / K-1) are fixed-length binary coded, so that each group index has the same number of codewords length, which is log2(M / K) bits. For example, for M=64, K=4, there are a total of 16 groups, so each group is assigned a 4-bit codeword.

[0156]

[0163] In another example, the group index (e.g., 0, 1,...,M / K-1) may be coded using a Golomb-Rice code with a divisor D (as described with respect to Golomb-Rice above), where D may be 1, 2, 4,...,M / K.

[0157]

[0164] In another example, the K split modes in a group can be ordered in ascending or descending order based on their original split mode indexes and assigned sub-mode indices accordingly. The sub-mode indices are then indicated in the bitstream by using a fixed-length binary code.

[0158]

[0165] In another example, instead of a fixed length code, the submode index codewords may be replaced by using a Golomb-Rice code with a divisor D (as described with respect to Golomb-Rice above), where D may be 1, 2, 4,...,M / K.

[0159]

[0166] In another example, instead of signaling a bit in the bitstream, the selection of the sub-mode index may be derived based on the TM cost. The TM cost may be calculated for each sub-mode. The sub-mode in the group that can generate the lowest TM cost is selected. For example, in the case of a grouping method for GEO partition modes, there may be an example where the video encoder 200 or the video decoder 300 may select group 0, which includes GEO partition modes 0 and 18, which may be selected by comparing the respective TM costs and accordingly selecting the one that achieves the lowest TM cost.

[0160]

[0167] In yet another example, the group index may also be reordered before being signaled and covered back after being parsed. In the video encoder 200, after the grouping is done, each submode in the group may derive its own TM cost, and the group index is reordered based on the best TM cost in each group. The reordered group index may then be signaled by using the aforementioned fixed-length binary code or Golomb-Rice code. In the video decoder 300, after the reordered group index is parsed, a mapping table (e.g., a mapping list) for group index reordering may be built in the same way as the encoder does. The reordered group index relies on this mapping table to map the reordered group index to an actual group index.

[0161]

[0168] In yet another example, a prefix code that may be applied to the group index, the reordered group index, and / or the sub-mode index may be context coded.

[0162]

[0169] The following describes cost (e.g., TM-cost) syntax reordering for GEO partitioning modes. In some examples, M partitioning mode indexes of a geometric partitioning mode (e.g., GEO, MMVD-GEO, TM-GEO) may be reordered based on their respective costs before signaling, where M is a positive number (e.g., 64 for VVC).

[0163]

[0170] In one example, the cost of each of the M partition mode indexes is first calculated, that is, the video encoder 200 and the video decoder 300 may determine a respective cost associated with each partition mode.

[0164]

[0171] Depending on the TM cost, the M split modes are sorted in ascending order, and thus a mapping table (e.g., a mapping list) is constructed to map the split mode index to the reordering index and vice versa. The reordering index is an index into the mapping table, and the split mode index is a value that indicates the split mode. For example, the split mode index is an index into Table 1 above that indicates the angle and offset for the edge of the split mode. The reordering index is then indicated in the bitstream by using a fixed length binary code, or by using a Golomb-Rice code with a divisor D (as described with respect to Golomb-Rice above), where D can be 1, 2, 4,..., M. In some examples, the divisor D is equal to 4.

[0165]

[0172] In other words, for each partition mode among at least two of the plurality of partition modes (e.g., a subset or all of the plurality of partition modes), the video encoder 200 and the video decoder 300 may determine a respective cost (e.g., a TM cost) associated with the respective partition mode and construct a mapping list having values ​​(e.g., a partition mode index) indicative of the partition mode based on the respective cost associated with the respective partition mode. In this example, to construct the mapping list, the video encoder 200 and the video decoder 300 may order the values ​​indicative of the partition mode in ascending order, starting from a value indicative of a partition mode having a lowest cost to a value indicative of a partition mode having a highest cost. In such an example, a partition mode having a lower cost may be associated with a lower index in the mapping list (i.e., the sorting indexes referred to above), while a partition mode having a higher cost may be associated with a higher index in the mapping list. For example, video encoder 200 and video decoder 300 may construct a mapping list including index values ​​respectively associated with values ​​indicating each partition mode based on the respective costs associated with each partition mode, with a lower index value in the mapping list being associated with a first partition mode having a lower cost than a second partition mode having a higher index value in the mapping list.

[0166]

[0173] In one or more examples, the video decoder 300 may determine an index value into the mapping list (e.g., the video encoder 200 may signal information indicating the index value into the mapping list). Because the order of the values ​​of the partition mode is reordered based on their respective costs, the index value into the mapping list may be considered as a reordered index value. From the index value into the mapping list, the video decoder 300 may determine a value indicative of the partition mode. The value indicative of the partition mode may be considered as a partition mode index. For example, the video decoder 300 may use the value indicative of the partition mode (e.g., the partition mode index) as an index into Table 1 above. From Table 1, the video decoder 300 may determine the angle and offset of the edge defined by the partition mode and partition the current block accordingly.

[0167]

[0174] As described above, video encoder 200 may encode the index value into the mapping list, while video decoder 300 may decode the index value. For example, to determine the index value into the mapping list, video decoder 300 may perform at least one of fixed-length binary decoding of information indicative of the index value, truncated binary decoding of information indicative of the index value, Golomb-Rice decoding of information indicative of the index value, or context-based adaptive coding (CABAC) decoding of one or more bins of information indicative of the index value.

[0168]

[0175] For example, in some examples, the video decoder 300 may CABAC decode all bins of the information indicating index values. In some examples, the video decoder 300 may CABAC decode some of the bins of the information indicating index values, while other bins may be bypass decoded. In some examples where some bins are CABAC decoded and other bins are bypass decoded, the leading bins may be CABAC decoded, while later bins may be bypass decoded.

[0169]

[0176] In another example, the cost of each of the M split mode indexes is first calculated. Depending on the cost, the M split modes are sorted in ascending order, and only the best N split modes are kept and all other split modes are removed, where N≦M. A mapping table (e.g., a mapping list) is then constructed to map these best N split mode indexes to their respective permutation indexes, and vice versa. The permutation index values ​​are then represented in the bitstream by using either a fixed-length binary code (when N is a power of 2), a shortened binary code (when N is not a power of 2), or by using a Golomb-Rice code with a divisor D (as described for Golomb-Rice), where D can be 1, 2, 4, . . . , M.

[0170]

[0177] Thus, in some examples, for each partition mode among at least two of the plurality of partition modes, the video encoder 200 and the video decoder 300 may determine a respective cost associated with the respective partition mode and construct a mapping list having a value indicative of the partition mode based on the respective cost associated with the respective partition mode. However, the video encoder 200 and the video decoder 300 may limit the size of the mapping list to the best N partition modes. The best N partition modes may be the N partition modes with the lowest costs. In some examples, the best N partition modes may be 32 partition modes.

[0171]

[0178] For example, the mapping list may include index values ​​(e.g., index values ​​in ascending order starting from 0). Each of the index values ​​represents an entry in the mapping list, and each entry in the mapping list may store a value indicative of a split mode. For example, an index value of 0 in the mapping list may point to a first entry in the mapping list, which may store a first value indicative of a first split mode. An index value of 1 in the mapping list may point to a second entry in the mapping list, which may store a second value indicative of a second split mode, and so on. Thus, the mapping list includes index values ​​each associated with a value indicative of a respective split mode.

[0172]

[0179] In one or more examples, a lower index value in the mapping list is associated with a first partitioning mode having a lower cost than a second partitioning mode having a higher index value in the mapping list. For example, as described above, a first value indicating the first partitioning mode may be stored in an entry in the mapping list identified by an index value of 0, while a second value indicating the second partitioning mode may be stored in an entry in the mapping list identified by an index value of 1. In this example, the first cost of the first partitioning mode is less than the second cost of the second partitioning mode.

[0173]

[0180] In yet another example, a prefix of a Golomb-Rice code that may be applied to the reordering index may be context coded. In yet another example, the configuration of the best N partition modes may be CU size dependent. In particular, the value of N for the larger block is generally equal to or greater than the value of N for the smaller block. Alternatively, in another example, the value of N for the larger block may be equal to or less than the value of N for the smaller block.

[0174]

[0181] In yet another example, the previous example may be applied directly to the submode index in the group (as described above with respect to the syntax reordering for GEO partitioning modes using grouping), and thus the definition of M is replaced by using the number of GEO partitioning modes in the group (e.g., the K value described above with respect to the syntax reordering for GEO partitioning using grouping).

[0175]

[0182] 10A-10D are conceptual diagrams illustrating an example of generating a reference template for determining the cost of a partition mode. For example, as described above, for each partition mode among at least two (e.g., a subset or all of the partition modes) of the plurality of partition modes, the video encoder 200 and the video decoder 300 may determine a respective cost associated with the respective partition mode, and then construct a mapping list having values ​​indicative of the respective partition modes based on the respective costs associated with the respective partition modes. For example, the video encoder 200 and the video decoder 300 may construct a mapping list including index values ​​respectively associated with values ​​indicative of the respective partition modes based on the respective costs associated with the respective partition modes, with a lower index value in the mapping list being associated with a first partition mode having a lower cost than a second partition mode having a higher index value in the mapping list. For example, an index value of 0 may be associated with a value indicative of a partition mode having the smallest cost, an index value of 1 may be associated with a value indicative of a partition mode having a second smallest cost, and so on.

[0176]

[0183] The following describes an example method for determining the costs associated with a partition mode. Video encoder 200 and video decoder 300 may repeat these example operations for a subset, or possibly all, of the multiple partition modes to determine respective costs associated with each partition mode.

[0177]

[0184] 10A shows a current block 1000. Video encoder 200 may determine that geometric partitioning mode is enabled for current block 1000 and signal such information to video decoder 300. Video decoder 300 may receive information indicating that geometric partitioning mode is enabled for current block 1000 and therefore determine that geometric partitioning mode is enabled for current block 1000. As described above and shown in FIG. 6, the geometric partitioning mode includes multiple partition modes that each define an edge for partitioning.

[0178]

[0185] For example, to determine the respective costs associated with the respective partition modes, the video encoder 200 and the video decoder 300 may start with one of a plurality of partition modes. As shown in FIG. 10A, the video encoder 200 and the video decoder 300 may set a current partition mode for determining the partition mode cost to a partition mode that defines an edge 1008. That is, the edge 1008 may correspond to a particular value indicating the partition mode. As an example, the edge 1008 may define an angle and offset that corresponds to a partition mode index (e.g., a value indicating the partition mode) in Table 1. For example, the edge 1008 may correspond to a partition mode A, where the value of A is one of the values ​​in Table 1 that defines the angle and offset for the edge 1008.

[0179]

[0186] It should be understood that the partition mode (e.g., partition mode A) that defines edge 1008 does not necessarily have to be the actual partition mode for the current block 1000. It is possible that the partition mode that defines edge 1008 is the actual partition mode of the current block 1000. Rather, in Figures 10A-10D, the partition mode that defines edge 1008 is the test partition mode that is used to determine the cost associated with that partition mode.

[0180]

[0187] Video encoder 200 and video decoder 300 may determine a current template 1004 for a current block 1000. For example, the current template 1004 may include samples above the current block 1000 and samples to the left of the current block 1000. As shown in FIG. 10A , the current template 1004 may include a top portion 1006A and a left portion 1006B. The portions 1006A and 1006B together form the current template 1004.

[0181]

[0188] According to one or more examples, the video encoder 200 and the video decoder 300 may determine respective reference templates based on the respective partition modes that define the edge 1008. The video encoder 200 and the video decoder 300 may determine respective costs associated with the respective partition modes that define the edge 1008 based on the respective reference templates and the current template 1004. An example of a respective reference template is the reference template 1018 of FIG. 10D, and an example method of generating the respective reference template 1018 is described below.

[0182]

[0189] In Figure 10A, an edge 1008 partitions a current block 1000 into a first partition 1002A and a second partition 1002B. As shown in Figure 10B, the first partition 1002A is associated with a first motion vector 1012A, and the second partition 1002B is associated with a second motion vector 1012B.

[0183]

[0190] From the perspective of the video decoder 300, when determining the respective costs of each partition mode for each of the partition modes among the multiple partition modes, the video decoder 300 may not yet have determined which partition mode to use. However, the video encoder 200 may have already signaled information indicating the motion vectors for the partitions. In other words, the video decoder 300 may determine that the geometric partition mode is enabled for the current block 1000 and therefore the current block 1000 should be partitioned into two partitions, and each partition should have a motion vector. Although the video decoder 300 may not have determined how to partition the current block 1000, the video decoder 300 may have already determined what the motion vectors are for each of the two partitions based on the information signaled by the video encoder 200 in the bitstream.

[0184]

[0191] As shown in FIG. 10B, the first motion vector 1012A identifies the first reference block 1010A, and the second motion vector 1012B identifies the second reference block 1010B. In the example of FIG. 10B, the first reference template 1014A includes a first portion of samples above the first reference block 1010A and a second portion of samples to the left of the first reference block 1010A. The second reference template 1014B includes a first portion of samples above the second reference block 1010B and a second portion of samples to the left of the second reference block 1010B. Thus, the video encoder 200 and the video decoder 300 may determine the first reference template 1014A based on the first reference block 1010A identified by the first motion vector 1012A of the first partition 1002A of the current block 1000. Similarly, video encoder 200 and video decoder 300 may determine a second reference template 1014B based on a second reference block 1010B identified by a second motion vector 1012B of a second partition 1002B of the current block 1000.

[0185]

[0192] In one or more examples, the video encoder 200 and the video decoder 300 may combine samples from the first reference template 1014A and the second reference template 1014B based on the respective partition modes to generate the respective reference templates. For example, with respect to a partition mode that defines an edge 1008, as shown in FIG. 10C, the video encoder 200 and the video decoder 300 may apply the partition mode that defines the edge 1008 to the first reference block 1010A. That is, the video encoder 200 and the video decoder 300 may partition the first reference block 1010A based on the edge 1008.

[0186]

[0193] The video encoder 200 and the video decoder 300 may extend the applied partitioning mode that defines the edge 1008 to samples of the first reference template 1014A. For example, as shown by line 1016A in FIG. 10C, the video encoder 200 and the video decoder 300 may extend the edge 1008 to an upper portion of the first reference template 1014A. In one or more examples, by extending the applied respective partitioning modes to samples of the first reference template 1014A, the video encoder 200 and the video decoder 300 may generate a first set 1018A of samples in the first reference template 1014A and a second set 1018B of samples in the first reference template 1014A.

[0187]

[0194] The video encoder 200 and the video decoder 300 may access a first set of samples in the first reference template 1014A based on an extension of the applied partition mode to the samples of the first reference template 1014A. For example, the line 1016A partitions the first reference template 1014A into a first portion and a second portion. As shown, the first set of samples 1018A is in the first portion of the first reference template 1014A to the right of the line 1016A, and the second set of samples 1018B is in the second portion of the first reference template 1014A to the left of the line 1016A.

[0188]

[0195] 10C, the first set of samples 1018A in the first reference template 1014A may be samples that the video encoder 200 and the video decoder 300 access. For example, the first portion including the first set of samples 1018A is based on an extension of a partition mode applied to the samples of the first reference template 1014A. The video encoder 200 and the video decoder 300 may access the first set of samples 1018A to generate a reference template used to determine a cost of a partition mode that defines the edge 1008.

[0189]

[0196] In one or more examples, the video encoder 200 and the video decoder 300 may access the first set of samples 1018A because the first reference block 1010A is from the motion vector 1012A of the first partition 1002A. The first partition 1002A is to the right of the current block 1000. Thus, the video encoder 200 and the video decoder 300 may access samples in the first portion (e.g., including the first set of samples 1018A) because the first portion is to the right of the line 1016A. That is, the first portion is in the same direction with respect to the line 1016A as the first partition 1002A is with respect to the edge 1008.

[0190]

[0197] 10C, the video encoder 200 and the video decoder 300 may apply a partition mode that defines the edge 1008 to the secondary reference block 1010B. That is, the video encoder 200 and the video decoder 300 may partition the secondary reference block 1010B based on the edge 1008.

[0191]

[0198] The video encoder 200 and the video decoder 300 may extend the applied partitioning mode that defines the edge 1008 to samples of the second reference template 1014B. For example, as shown by line 1016B in FIG. 10C, the video encoder 200 and the video decoder 300 may extend the edge 1008 to an upper portion of the second reference template 1014B. In one or more examples, by extending the respective applied partitioning modes to samples of the second reference template 1014B, the video encoder 200 and the video decoder 300 may generate a third set 1020B of samples in the second reference template 1014B and a fourth set 1020A of samples in the second reference template 1014B.

[0192]

[0199] The video encoder 200 and the video decoder 300 may access the third set of samples 1020B in the second reference template 1014B based on the extension of the applied partition mode to the samples of the second reference template 1014B. For example, the line 1016B partitions the second reference template 1014B into a first portion including the fourth set of samples 1020A and a second portion including the third set of samples 1020B. As shown, the first portion includes the portion of the second reference template 1014B to the right of the line 1016B, and the second portion includes the portion of the second reference template 1014B to the left of the line 1016B.

[0193]

[0200] 10C, the second portion includes a third set 1020B of samples in the second reference template 1014B that the video encoder 200 and the video decoder 300 access. For example, the third set of samples 1020B is based on an extension of a partition mode applied to the samples of the second reference template 1014B. The video encoder 200 and the video decoder 300 may access the third set of samples 1020B to generate a reference template used to determine a cost of a partition mode that defines the edge 1008.

[0194]

[0201] In one or more examples, the video encoder 200 and the video decoder 300 may access samples in the portion including the third set of samples 1020B because the second reference block 1010B is from the motion vector 1012B of the second partition 1002B. The second partition 1002B is to the left of the current block 1000. Thus, the video encoder 200 and the video decoder 300 may access the third set of samples 1020B because the portion including the third set of samples 1020B is to the left of the line 1016B. That is, the portion including the third set of samples 1020B is in the same direction relative to the line 1016B as the second partition 1002B is relative to the edge 1008.

[0195]

[0202] 10D, the video encoder 200 and the video decoder 300 may combine the first set of samples 1018A and the third set of samples 1020B to generate a reference template 1022 that is used to determine a cost of the partitioning mode that defines the edge 1008. For example, as shown in FIG. 10D, the first set of samples 1018A and the third set of samples 1020B may together form the reference template 1022.

[0196]

[0203] For example, and merely for ease of understanding, Figure 10D shows line 1016C corresponding to lines 1016A and 1016B. In the reference template 1022, the samples to the right of line 1016C are one or more samples from the first set of samples 1018A. In the reference template 1022, the samples to the left of line 1016C are one or more samples from the third set of samples 1020B.

[0197]

[0204] In the example of FIG. 10D, the video encoder 200 and the video decoder 300 may generate the reference template 1022 by utilizing sample values ​​of samples in the first set of samples 1018A and samples in the second set of samples 1020B, possibly without further filtering or weighting. However, the example technique is not so limited. In some examples, such as samples near the line 1016C, the video encoder 200 and the video decoder 300 may blend one or more samples in the first set of samples 1018A with one or more samples in the fourth set of samples 1020A. For samples near the line 1016C, the video encoder 200 and the video decoder 300 may blend one or more samples in the third set of samples 1020B with one or more samples in the second set of samples 1018B. The video encoder 200 and the video decoder 300 may combine the first set of samples 1018A and the third set of samples based on the weightings to generate the reference template 1022.

[0198]

[0205] Using the reference template 1022, the video encoder 200 and the video decoder 300 may determine a cost associated with the partition mode that defined the edge 1008. For example, the video encoder 200 and the video decoder 300 may compare (e.g., determine a sum of absolute differences (SAD) or do some other calculation) the reference template 1022 to a current template 1004 that includes samples above and to the left of the current block 1000, as shown in FIG. 10A. The video encoder 200 and the video decoder 300 may determine a cost of the partition mode that defines the edge 1008 based on the comparison (e.g., the SAD value).

[0199]

[0206] 10A-10D thus illustrate example operations that video encoder 200 and video decoder 300 may perform to determine a cost associated with a first partition mode (e.g., the partition mode that defines edge 1008). Video encoder 200 and video decoder 300 may repeat such operations for all or a subset of a plurality of partition modes to determine a respective cost for each of the partition modes. As an example, as a result of performing the example operations of FIGS. 10A-10D, video encoder 200 and video decoder 300 may determine a cost X of partition mode A, where A is a value indicative of the partition mode, and a cost Y of partition mode B, where B is a value indicative of the partition mode, and so on.

[0200]

[0207] Video encoder 200 and video decoder 300 may construct a mapping list based on the respective costs. For example, assume that cost Y is less than cost X. In this example, video encoder 200 and video decoder 300 may include a partition mode B (e.g., a value indicating partition mode B) before a partition mode A (e.g., a value indicating partition mode A). In this example, the values ​​for A and B (e.g., for partition modes A and B) may be examples of partition mode indexes. For example, the value of A may be one of the values ​​in Table 1, and the value of B may be another one of the values ​​in Table 1. Based on the values ​​from the mapping list, video decoder 300 may determine one partition mode of a plurality of partition modes.

[0201]

[0208] For example, assume that partition mode B is located at index 2 (e.g., the third entry) in the mapping list. In this example, if video decoder 300 receives an index of 2, video decoder 300 may determine that the partition mode is partition mode B. Video decoder 300 may then use the value of "B" as the partition mode index into Table 1 and determine the angle and offset for the edge defined by partition mode B. Video decoder 300 may then partition the current block (e.g., current block 1000) based on the edge defined by partition mode B and reconstruct current block 1000 based on partitions 1002A, 1002B.

[0202]

[0209] FIG. 11 is a flowchart illustrating an example of constructing a mapping list for a partition mode. In the example of FIG. 11, the video encoder 200 or the video decoder 300 may determine a cost for a current partition mode (1100). For example, the video encoder 200 and the video decoder 300 may perform the example operations described above with respect to FIG. 10A-10D to determine a cost for the current partition mode. For example, the video encoder 200 and the video decoder 300 may determine a reference template, such as the reference template 1022, based on the current partition mode (e.g., based on an edge, such as the edge 1008, of the current partition mode). The video encoder 200 and the video decoder 300 may determine a current template (e.g., the current template 1004) and determine a cost associated with the current partition mode based on the reference template and the current template.

[0203]

[0210] The video encoder 200 and the video decoder 300 may determine whether there are more partition modes (1102). For example, there may be 64 partition modes, and the video encoder 200 and the video decoder 300 may determine whether the video encoder 200 and the video decoder 300 have determined a cost for each of the 64 partition modes. In some examples, a subset of the partition modes may be considered, rather than all 64 partition modes.

[0204]

[0211] If there are more partition modes whose costs have not yet been determined ("Yes" at 1102), the video encoder 200 and the video decoder 300 may set the next partition mode as the current partition mode (1104). The video encoder 200 and the video decoder 300 may determine the cost of the current partition mode (1100) and repeat such operations until there are no more partition modes.

[0205]

[0212] In this manner, for each partition mode among at least two of the plurality of partition modes, the video encoder 200 and the video decoder 300 may determine a respective cost associated with the respective partition mode. For example, each cycle through the operations of 1100 and 1104 corresponds to a determination of a respective cost associated with each partition mode among the plurality of partition modes. As an example, during a first pass through the operations of 1100 and 1104, the video encoder 200 and the video decoder 300 may determine a first reference template (e.g., such as reference template 1022) based on the first partition mode and determine a first cost based on the first reference template and the current template 1004. During a second pass through the operations of 1100 and 1104, the video encoder 200 and the video decoder 300 may determine a second reference template (e.g., such as reference template 1022) based on the second partition mode and determine a second cost based on the second reference template and the current template 1004, and so on.

[0206]

[0213] If there are no more partition modes for which costs have not yet been determined ("NO" at 1102), the video encoder 200 and the video decoder 300 may build a mapping list (1106). In the example of FIG. 11, building the mapping list is shown as occurring after each cost determination. However, the example techniques are not so limited, and the video encoder 200 and the video decoder 300 may build the mapping list as part of determining the costs (e.g., by successively reordering the list based on each new determined cost).

[0207]

[0214] To construct the mapping list, the video encoder 200 and the video decoder 300 may order one or more of the partition modes in ascending order based on their respective costs. For example, the video encoder 200 and the video decoder 300 may form the mapping list such that a first entry in the mapping list (e.g., index value 0) includes a value indicating a partition mode having the lowest cost, a second entry in the mapping list (e.g., index value 1) includes a value indicating a partition mode having the second lowest cost, and so on. In this manner, the video encoder 200 and the video decoder 300 may construct a mapping list including index values ​​respectively associated with values ​​indicating the respective partition modes based on the respective costs associated with the respective partition modes, with a lower index value in the mapping list being associated with a first partition mode having a lower cost than a second partition mode having a higher index value in the mapping list.

[0208]

[0215] In some examples, the video encoder 200 and the video decoder 300 may continue to add up the values ​​indicating the respective costs until there are N values. In other words, to construct the mapping list, the video encoder 200 and the video decoder 300 may include the N partition modes with the lowest costs. As an example, N is equal to 32.

[0209]

[0216] As described above, the video encoder 200 and the video decoder 300 may determine a cost based on a respective reference template (such as, for example, the reference template 1022) and the current template 1004. Below, an example of the cost calculation is described. For simplicity, the following is described with respect to the reference template 1022, with the understanding that similar operations may be performed for each reference template for each split mode.

[0210]

[0217] In one example, as described with respect to Figure 10D, the reference template 1022 may include samples from the first set of samples 1018A of the first reference template 1014A and samples from the third set of samples 1020B of the second reference template 1014B. A cost is then derived based on the difference between the current template 1004 and each reference block template.

[0211]

[0218] However, also as described above, in one example, the reference block templates are first blended using GEO weights, i.e., samples from the first set of samples 1018A and the third set of samples 1020B proximate the line 1016 are blended using weights defined for the geometric partitioning mode. A cost is then derived based on the difference between the current template 1004 and each blended reference block template.

[0212]

[0219] The cost (e.g., difference metric) may be SAD, SATD, SSE, mean removed SAD, mean removed SATD, or mean removed SSE, which may be formulated as follows: Σ (i,j)∈T |C(i,j)-Clip((w 0 (i,j) * P 0 (vx 0 +i,vy 0 +j)+w 1 (i,j)* P 1 (vx 1 +i,vy 1 +j)+o)>>s)|,

[0213]

[0220] where T = {(0,-t),(block width -1,-t),(-t,0),···,(-t,block height -1)|∀t = 1,···,maximum template size}, C(i,j) denotes the reconstructed intensity value of the sample located at (i,j) relative to the top-left sample of the current block, and P n (vx n +i,vy n +j) is the motion vector (vx n ,vy n ) indicates the intensity value of the sample located at (i,j) relative to the top-left sample of the reference block pointed to by P 0 and P 1 predSamplesLA L and predSamplesLB L Using the same VVC specification JVET-T2001 subclause 8.5.7.1, different array sizes (i.e., the aforementioned T) are generated and w n (i,j) is the sample P n (vx n +i,vy n +j) and w 1 (i,j)=8-w 0 Corresponding to (i,j), is the value of the GEO weight to be applied (as described above with respect to the use of GEO weights for blending reference block templates), t ranges from 1 to some positive number determined by the maximum size of the template, s and o are defined as shift1 and offset1, respectively, which are the same as equations (992) and (993) in the VVC specification JVET-T2001, and Clip is a function that changes the input value from 0 to 2^ BitDepth This function clips the value to within the range of -1 or less.

[0214]

[0221] In one example, difference block templates are first generated. The difference block templates (i.e., one for the top template and the other for the left template) are the delta differences between the current block template and the reference block template. Since GEO has two partitions, there are two sets of difference block templates (e.g., one set for one partition and the other set for the other partition).

[0215]

[0222] Stated another way, in some examples, the video encoder 200 and the video decoder 300 may determine a difference between the current template 1004 and the first reference template 1014A and determine a difference between the current template 1004 and the second reference template 1014B. The video encoder 200 and the video decoder 300 may then perform the blending.

[0216]

[0223] Then, a blending process is applied to blend the two sets of difference block templates, and then the TM cost is the sum of all values ​​on the blended difference block templates, which can be formulated as follows: Σ (i,j)∈T w 0 (i,j) * |C(i,j)-Clip((P 0 (vx 0 +i,vy 0 +j)+o)>>s)|+w 1 (i,j) * |C(i,j)-Clip((P 1 (vx 1 +i,vy 1 +j)+o)>>s)|,

[0217]

[0224] In the above, P 0 and P 1are generated as if they were two uni-predictive templates, and therefore their bit-depth is the same as the bit-depth of the current template C, and their o and s are specified as s=Max(2,14-bitDepth) and o=1<<(s-1).

[0218]

[0225] In another example, for simplicity, the reference block template is interpolated towards a predefined bit depth (e.g., 8 bits, 10 bits, 12 bits, 14 bits, or higher bit depth), and the current block template is also shifted to match the predefined bit depth. Then, the TM cost is calculated at the predefined bit depth. To achieve this, the respective settings of the bit depth used in the above example for s and o must be set equal to the predefined bit depth, and C(i,j) may be shifted left or right depending on whether the original bit depth or the predefined bit depth is larger. For example, C(i,j) is shifted left by 2 bits if the predefined bi-depth is 2 greater than the original bi-depth.

[0219]

[0226] For simplicity, the TM cost considers only a portion of the samples on the template, rather than the complete sample. In one example, samples located in the top template are not considered. b. In another example, samples located in the left template are not considered. c. In another example, samples with odd (or even) row indexes in both the left and top templates are not considered in the TM cost calculation. Alternatively, in yet another example, a subsampling rule is applied to the left template. Alternatively, in yet another example, a subsampling rule is applied to the top template. d. In another example, samples with odd (or even) column indexes in both the left and top templates are not considered in the TM cost calculation. Alternatively, in yet another example, a subsampling rule is applied to the left template. Alternatively, in yet another example, a subsampling rule is applied to the top template.

[0220]

[0227] The use of GEO weights for blending reference block templates is described below. This disclosure describes various methods for deriving weight values ​​used in the reference block template blending process.

[0221]

[0228] In one example, weight values ​​associated with sample positions outside the current block are also calculated by using the same equation that VVC GEO uses for derived weight values. That is, when performing blending of one or more samples of the first set of samples 1018A of the first reference template 1014A with one or more samples of the third set of samples 1020B of the second reference template 1014B near the line 1016C, the video encoder 200 and the video decoder 300 may use the VVC sample equation for weighting.

[0222]

[0229] Specifically, this amendment requires adding another construction for equations (1002)-(1007) in the VVC specification JVET-T2001. <add> ...< / add> The bold italicized parts in indicate the differences between this example and equations (1002) to (1007). <add>The prediction samples of top reference template block pbSamples[x][y] with x = 0..nCbW-1 and y = -1 and the prediction samples of left reference template block pbSamples[x][y] with x = -1 and y = 0..nCbH-1 are derived as follows:< / add> The variables xL and yL are derived as follows: xL=(cIdx==0)?x:x * SubWidthC yL=(cIdx==0)?y:y * SubHeightC The variable wValue, which specifies the weight of the prediction samples, is derived based on the array disLut specified in Table 37 of JVET-T2001 as follows: weightIdx=(((xL+offsetX)<<1)+1) * disLut[displacementX]+ (((yL+offsetY)<<1)+1) * disLut[displacementY] weightIdxL=partFlip?32+weightIdx:32-weightIdx wValue=Clip3(0,8,(weightIdxL+4)>>3) The predicted sample values ​​are derived as follows: pbSamples[x][y]=Clip3(0,(1< <BitDepth)-1,(predSamplesLA[x][y] * wValue+ predSamplesLB[x][y] * (8-wValue)+offset1)>>shift1)

[0223] [Table 7]

[0224]

[0230] In one example, for simplicity, the weight values ​​associated with the boundary samples in the current block are reused. Thus, there is no extra complexity to derive weight values ​​for blending the reference block template. For example, when the template size is one line, the weight values ​​applied to the first row of the block are directly applied to the top reference block template, and the weight values ​​applied to the first left column of the block are directly applied to the left reference block template. In another example, when the template size is greater than one line, each line of the top reference template block shares the same weight value as the weight value of the first top row in the current block. Similarly, each line of the left reference template block shares the same weight value as the weight value of the first left column in the current block. The following<add> ...< / add> The bold italicized parts within the section indicate the differences between this example and equations (1002)-(1007). <ADD.The prediction samples of top reference template block pbSamples[x][y]with x=0..nCbW-1 and y=-1 and the prediction samples of left reference template block pbSamples[x][y]with x=-1 and y=0..nCbH-1 are derived as follows: The variables xL and yL are derived as follows: <add>xD=(is top reference block?x:0) yD=(is top reference block?0:y)< / add> xL=(cIdx==0)? <add>xD:xD< / add> * SubWidthC yL=(cIdx==0)? <add>yD:yD< / add> * SubHeightC The variable wValue, which specifies the weight of the prediction samples, is derived based on the array disLut specified in Table 37 of JVET-T2001 as follows: weightIdx=(((xL+offsetX)<<1)+1) * disLut[displacementX]+ (((yL+offsetY)<<1)+1) * disLut[displacementY] weightIdxL=partFlip?32+weightIdx:32-weightIdx wValue=Clip3(0,8,(weightIdxL+4)>>3) The predicted sample values ​​are derived as follows: pbSamples[x][y]=Clip3(0,(1< <BitDepth)-1,(predSamplesLA[x][y] * wValue+ predSamplesLB[x][y] *(8-wValue)+offset1)>>shift1)

[0225]

[0231] In another example, for simplicity, only weight values ​​0 and 8 are used, which means that no blending is applied to samples along the GEO division edges. For example, when no weighting is applied, the reference template 1022 includes samples of the first set of samples 1018A of the first reference template 1014A and samples of the third set of samples 1020B of the second reference template 1014B without blending the samples with each other. Each sample on the reference template 1022 is simply selected from a reference template of either the first GEO partition or the other GEO partition (e.g., from either the first reference template 1014A or the second reference template 1014B), thus completely avoiding the multiplications used in the blending process. Specifically, this modification requires adding another configuration for equations (1002)-(1007) in the VVC specification JVET-T2001. The following <add> ...< / add> The bold italicized parts within the section indicate the differences between this example and equations (1002)-(1007). <add>The prediction samples of top reference template block pbSamples[x][y] with x = 0..nCbW-1 and y = -1 and the prediction samples of left reference template block pbSamples[x][y] with x = -1 and y = 0..nCbH-1 are derived as follows:< / add> The variables xL and yL are derived as follows: xL=(cIdx==0)?x:x * SubWidthC yL=(cIdx==0)?y:y * SubHeightC The variable wValue specifying the weights of the prediction samples is derived based on the array disLut specified in Table 37 as follows: weightIdx=(((xL+offsetX)<<1)+1) * disLut[displacementX]+ (((yL+offsetY)<<1)+1) * disLut[displacementY] <add>wValue = partFlip?(weightIdx>0?8:0):(weightIdx>0?0:8)< / add> The predicted sample values ​​are derived as follows: pbSamples[x][y]=Clip3(0,(1< <BitDepth)-1,(predSamplesLA[x][y] * wValue+ predSamplesLB[x][y] * (8-wValue)+offset1)>>shift1)

[0226]

[0232] Another example is a combination of the above examples. <add>The prediction samples of top reference template block pbSamples[x][y] with x = 0..nCbW-1 and y = -1 and the prediction samples of left reference template block pbSamples[x][y] with x = -1 and y = 0..nCbH-1 are derived as follows:< / add> The variables xL and yL are derived as follows: <add>xD=(is top reference block?x:0) yD=(is top reference block?0:y)< / add> xL=(cIdx==0)? <add>xD:xD< / add> * SubWidthC yL=(cIdx==0)? <add>yD:yD< / add> * SubHeightC The variable wValue specifying the weights of the prediction samples is derived based on the array disLut specified in Table 37 as follows: weightIdx=(((xL+offsetX)<<1)+1) * disLut[displacementX]+ (((yL+offsetY)<<1)+1) * disLut[displacementY] <add>wValue = partFlip?(weightIdx>0?8:0):(weightIdx>0?0:8)< / add> The predicted sample values ​​are derived as follows: pbSamples[x][y]=Clip3(0,(1< <BitDepth)-1,(predSamplesLA[x][y] * wValue+ predSamplesLB[x][y] * (8-wValue)+offset1)>>shift1)

[0227]

[0233] In another example, as a simplification of the above technique, after the formula "wValue=Clip3(0,8,(weightIdxL+4)>>3)" is processed, the value of wValue may be further updated. Specifically, the update operation is "wValue=wValue<4?0:8" or "wValue=wValue≦4?0:8".

[0228]

[0234] The application to GEO+TM mode will be described below. In one example, the partition mode coding method described in Grouping for GEO Partition Mode and Syntax Reordering for GEO Partition Mode Using TM Cost-Based Syntax Reordering can be applied to GEO+TM where the used motion information of the two GEO partitions is not refined. The unrefined motion information is used to generate a reference block template for TM cost calculation.

[0229]

[0235] In one example, the partition mode coding method described in Grouping for GEO Partition Mode and Syntax Reordering for GEO Partition Mode Using TM Cost-Based Syntax Reordering can be applied to GEO+TM, where the used motion information of the two GEO partitions is refined. The refined motion information is used to generate a reference block template for TM cost calculation.

[0230]

[0236] The following describes the interaction between reference picture resampling (RPR) and TM cost-based GEO partition mode reordering. Some of the example techniques may be related to U.S. Provisional Application No. 63 / 265,555, filed December 16, 2021, the contents of which are incorporated herein by reference. The examples listed below disclose template matching (TM) prediction RPR restrictions to determine whether TM can be applied based on the respective picture sizes of the current picture and the reference picture(s).

[0231]

[0237] In one example, the GEO partition modes are no longer sorted based on TM cost when the reference picture size is different from the current one, but rather a default order (e.g., from smaller partition mode index to larger partition mode index) is assigned to all candidates for GEO, GEO+MMVD, and GEO+TM modes.

[0232]

[0238] In another example, GEO partition modes are no longer sorted based on TM cost when reference pictures are applied with WP, but rather a default order (e.g., from smaller partition mode index to larger partition mode index) is assigned to all candidates for GEO, GEO+MMVD, and GEO+TM modes.

[0233]

[0239] Next, an extension is described. Similar concepts described above with respect to TM cost-based syntax reordering for GEO partitioning mode can be utilized to improve the coding performance of candidate indexes for GEO, GEO+MMVD, and GEO+TM modes. The reordering concepts are applied to GEO candidates instead of GEO partitioning mode in the following examples.

[0234]

[0240] For GEO, GEO+MMVD, and GEO+TM modes, they all require signaling a pair of merge indices to indicate the use of merge candidates for both GEO partitions. In this example, for each pair of merge indices, GEO generates reference block templates for both partitions to calculate TM cost. The way in which TM cost is calculated (as described above for TM cost calculation) and template block weight usage (as described above for GEO weight usage for blending reference block templates) can be combined in this example. Then, TM cost can be used to sort all pairs in ascending order and assign a sorting index accordingly. Then, similar to the TM cost based syntax sorting for GEO partitioning mode, this sorting index can be coded by using a fixed length binary code or a Golomb-Rice code with divisor D (as described above for Golomb-Rice), where D can be 1, 2, 4, ..., M. In some examples, D is equal to 4.

[0235]

[0241] In another example, as an extension of the above example, only the best N candidates that achieve a lower TM cost than the others are identified (the others are removed) and signaled by using a fixed-length binary code (if N is a power of 2), a shortened binary code (if N is a non-power of 2), or a Golomb-Rice code with divisor D (discussed above with respect to Golomb-Rice), where D can be 1, 2, 4,...,M.

[0236]

[0242] For GEO+MMVD, there are multiple choices of offsets (called MVD offsets) that can be added to either or both of the selected merge candidates. In ECM, there are 73 choices (including zero MVD offsets) for each of the GEO partitions. Thus, there are a total of 5329 (=73×73) modes to be signaled. In this example, the TM cost of each of the 5329 modes is calculated and the best N of them are identified for signaling. The signaling method can be a fixed-length binary code (if N is a power of 2), a shortened binary code (if N is not a power of 2), or a Golomb-Rice code with divisor D (as described above for Golomb-Rice), where D can be 1, 2, 4, . . . , M.

[0237]

[0243] In another example in addition to the previous one, zero MVD offsets are excluded from sorting, and thus only the 72x72 mode is present as participating in the sorting process. Instead of sorting all possible combinations of GEO candidates, the following example involves sorting the GEO partition candidates independently.

[0238]

[0244] For GEO, GEO+MMVD, and GEO+TM modes, they all require signaling a pair of merge indices to indicate the use of merge candidates for both GEO partitions. Assuming there are N candidates per GEO partition, the respective TM costs are calculated for these N candidates. Then, the best N of them are identified for signaling. The signaling method can be a fixed-length binary code (when N is a power of 2), a shortened binary code (when N is not a power of 2), or a Golomb-Rice code with divisor D (as described above for Golomb-Rice), where D can be 1, 2, 4, ..., M. There are two different methods to calculate the TM cost: a. The TM cost is the sum of the absolute differences between the reference block template and the current block template of the GEO partition. The subsampling of the TM cost disclosed above for the TM cost calculation can be combined together. This can be formulated as follows: Σ (i,j)∈T |C(i,j)-Clip((P(vx+i,vy+j)+o)>>s)|, where T = {(0, -t), (block width -1, -t), (-t, 0), · · ·, (-t, block height -1) | ∀t = 1, · · ·, maximum template size}, C(i, j) denotes the reconstructed intensity value of the sample located at (i, j) relative to the top-left sample of the current block, P(vx + i, vy + j) denotes the intensity value of the sample located at (i, j) relative to the top-left sample of the reference block pointed to by the motion vector (vx, vy), P is generated as if it were a uni-predictive template and therefore its bit depth is identical to the bit depth of the current template C (hence s = Max(2, 14-bitDepth) and o = 1 << (s-1)), and t ranges from 1 to some positive number determined by the maximum size of template C. b. The TM cost is the sum of weighted absolute differences between the reference block template and the current block template of the GEO partition. This can be formulated as follows: Σ (i,j)∈T w(i,j) * |C(i,j)-Clip((P(vx+i,vy+j)+o)>>s)|, where w(i,j) is the GEO weight value corresponding to the sample located at (i,j) on the current block template.

[0239]

[0245] As mentioned above, for GEO+MMVD, there are multiple choices of offsets (called MVD offsets) that can be added to one or both of the selected merge candidates. Assuming there are N MVD offsets per GEO partition (whether including or excluding zero MVD offsets), the respective TM costs are calculated for these N candidates. Then, the best N of them are identified for signaling. The signaling method can be a fixed-length binary code (if N is a power of 2), a shortened binary code (if N is not a power of 2), or a Golomb-Rice code with divisor D (as described above for Golomb-Rice), where D can be 1, 2, 4, ..., M. There are two different methods to calculate the TM cost, identical to those described in the previous example.

[0240]

[0246] 2 is a block diagram illustrating an example video encoder 200 capable of implementing the techniques of this disclosure. FIG. 2 is provided for purposes of illustration 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 implemented by video encoding devices configured for other video coding standards and video coding formats, such as AV1 and successors of the AV1 video coding format.

[0241]

[0247] 2, the video encoder 200 includes a video data memory 230, a mode selection unit 202, a residual generation unit 204, a transform processing unit 206, a quantization unit 208, an inverse quantization unit 210, an inverse transform processing unit 212, a reconstruction unit 214, a filter unit 216, a decoded picture buffer (DPB) 218, and an entropy coding unit 220. Any or all of the video data memory 230, the mode selection unit 202, the residual generation unit 204, the transform processing unit 206, the quantization unit 208, an inverse quantization unit 210, an inverse transform processing unit 212, a reconstruction unit 214, a filter unit 216, a DPB 218, and an entropy coding unit 220 may be implemented in one or more processors or processing circuits. For example, the units of the video encoder 200 may be implemented as one or more circuits or logic elements as part of a hardware circuit, or as part of a processor, an ASIC, or an FPGA. Moreover, video encoder 200 may include additional or alternative processors or processing circuitry for performing these and other functions.

[0242]

[0248] The video data memory 230 may store video data to be encoded by the components of the video encoder 200. The video encoder 200 may receive the video data stored in the video data memory 230 from, for example, the video source 104 (FIG. 1). The DPB 218 may act as a reference picture memory, storing reference video data for use in predicting subsequent video data by the video encoder 200. The video data memory 230 and the DPB 218 may be formed by any of 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. The video data memory 230 and the DPB 218 may be provided by the same memory device or separate memory devices. In various examples, the video data memory 230 may be on-chip with other components of the video encoder 200, as shown, or may be off-chip relative to those components.

[0243]

[0249] In this disclosure, references to video data memory 230 should not be construed as limited to memory internal to video encoder 200, unless specifically stated as such, or to memory external to video encoder 200, unless specifically stated as such. 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 a current block to be encoded). Memory 106 of FIG. 1 may also provide temporary storage of outputs from various units of video encoder 200.

[0244]

[0250] The various units in FIG. 2 are shown to aid in understanding the operations performed by the video encoder 200. The units may be implemented as fixed-function circuits, programmable circuits, or a combination thereof. A fixed-function circuit refers to a circuit that provides a specific functionality, and the operations that it can perform are predefined. A programmable circuit refers to a circuit that can be programmed to perform a variety of tasks, and provides flexible functionality in the operations that it can perform. 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 a fixed-function circuit may execute software instructions (e.g., to receive parameters or output parameters), the type of operations that the fixed-function circuit performs is generally unchanged. In some examples, one or more of the units may be separate circuit blocks (fixed function or programmable), and in some examples, one or more of the units may be an integrated circuit.

[0245]

[0251] Video encoder 200 may include arithmetic logic units (ALUs), elementary functional units (EFUs), digital circuits, analog circuits, and / or a programmable core formed from programmable circuits. In examples in which the operations of video encoder 200 are implemented using software executed by programmable circuits, memory 106 (FIG. 1) may store 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.

[0246]

[0252] The video data memory 230 is configured to store the received video data. The video encoder 200 may retrieve pictures of the video data from the video data memory 230 and provide the video data to the residual generation unit 204 and the mode selection unit 202. The video data in the video data memory 230 may be raw video data to be encoded.

[0247]

[0253] The mode selection unit 202 includes a motion estimation unit 222, a motion compensation unit 224, and an intra prediction unit 226. The mode selection unit 202 may include additional functional units for performing video prediction according to other prediction modes. By way of example, the mode selection unit 202 may include a palette unit, an intra block copy unit (which may be part of the motion estimation unit 222 and / or the motion compensation unit 224), an affine unit, a linear model (LM) unit, etc.

[0248]

[0254] The mode selection unit 202 typically coordinates multiple encoding passes to test combinations of encoding parameters and the rate-distortion values ​​obtained for such combinations. The encoding parameters may include partitioning of the CTUs into CUs, prediction modes for the CUs, transform types for residual data of the CUs, quantization parameters for residual data of the CUs, etc. The mode selection unit 202 may ultimately select a combination of encoding parameters that has a better rate-distortion value than the other tested combinations.

[0249]

[0255] Video encoder 200 may partition a picture retrieved from video data memory 230 into a series of CTUs and may encapsulate one or more CTUs within a slice. Mode select unit 202 may partition the CTUs of a picture according to a tree structure, such as the MTT structure, the QTBT structure, the superblock structure, or the quadtree structure described above. As described above, video encoder 200 may form one or more CUs from partitioning the CTUs according to the tree structure. Such CUs may also be generally referred to as "video blocks" or "blocks."

[0250]

[0256] In general, the mode selection unit 202 also controls its components (e.g., the motion estimation unit 222, the motion compensation unit 224, and the intra prediction unit 226) to generate a prediction block for a current block (e.g., the current CU, or in HEVC, the overlapping portion of the PU and TU). In the case of inter prediction of the current block, the motion estimation unit 222 may perform motion search to identify one or more closely matching reference blocks among one or more reference pictures (e.g., one or more previously coded pictures stored in the DPB 218). Specifically, the motion estimation unit 222 may calculate a value representing how similar a potential reference block is to the current block according to, for example, a sum of absolute differences (SAD), a sum of squared differences (SSD), a mean absolute difference (MAD), a mean squared difference (MSD), etc. The motion estimation unit 222 may generally perform these calculations using a sample-by-sample difference between the current block and the reference block under consideration. Motion estimation unit 222 may identify the reference block having the lowest value resulting from these calculations, which indicates the reference block that best matches the current block.

[0251]

[0257] The motion estimation unit 222 may form one or more motion vectors (MVs) that define the position of a reference block in a reference picture relative to the position of a current block in a current picture. The motion estimation unit 222 may then provide the motion vectors to the motion compensation unit 224. For example, in the case of unidirectional inter prediction, the motion estimation unit 222 may provide a single motion vector, while in the case of bidirectional inter prediction, the motion estimation unit 222 may provide two motion vectors. The motion compensation unit 224 may then generate a predictive block using the motion vectors. For example, the motion compensation unit 224 may retrieve data of a reference block using the motion vectors. As another example, if the motion vectors have fractional sample precision, the motion compensation unit 224 may interpolate values ​​for the predictive block according to one or more interpolation filters. Moreover, in the case of bidirectional inter prediction, the motion compensation unit 224 may retrieve data for two reference blocks identified by the respective motion vectors and combine the retrieved data, for example, through a sample-wise average or weighted average.

[0252]

[0258] When operating according to the AV1 video coding format, the motion estimation unit 222 and the motion compensation unit 224 may be configured to encode coding blocks of video data (e.g., both luma coding blocks and chroma coding blocks) using translational motion compensation, affine motion compensation, overlapped block motion compensation (OBMC), and / or synthetic inter-intra prediction.

[0253]

[0259] As another example, in the case of intra prediction or intra predictive coding, the intra prediction unit 226 may generate a predictive block from samples neighboring the current block. For example, in the case of a directional mode, the intra prediction unit 226 may generally mathematically combine values ​​of neighboring samples to populate these calculated values ​​in a defined direction across the current block to produce a predictive block. As another example, in the case of a DC mode, the intra prediction unit 226 may calculate an average of samples neighboring the current block and generate a predictive block to include this resulting average for each sample of the predictive block.

[0254]

[0260] When operating according to the AV1 video coding format, intra prediction unit 226 may be configured to encode coding blocks of video data (e.g., both luma coding blocks and chroma coding blocks) using directional intra prediction, non-directional intra prediction, recursive filter intra prediction, chroma-from-luma (CFL) prediction, intra block copy (IBC), and / or color palette modes. Mode selection unit 202 may include additional functional units for performing video prediction according to other prediction modes.

[0255]

[0261] The mode selection unit 202 provides the prediction block to the residual generation unit 204. The residual generation unit 204 receives a raw uncoded version of the current block from the video data memory 230 and receives the prediction block from the mode selection unit 202. The residual generation unit 204 calculates sample-by-sample differences between the current block and the prediction block. The resulting sample-by-sample differences define a residual block for the current block. In some examples, the residual generation unit 204 may also determine differences between sample values ​​in the residual block to generate the residual block using residual differential pulse code modulation (RDPCM). In some examples, the residual generation unit 204 may be formed using one or more subtractor circuits that perform binary subtraction.

[0256]

[0262] In an example where the mode select unit 202 partitions a CU into PUs, each PU may be associated with a luma prediction unit and a corresponding chroma prediction unit. The video encoder 200 and the video decoder 300 may support PUs having 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 a PU may refer to the size of the luma prediction unit of the PU. Assuming that the size of a particular CU is 2N×2N, the video encoder 200 may support a PU size of 2N×2N or N×N for intra prediction, and a symmetric PU size of 2N×2N, 2N×N, N×2N, N×N, or similar for inter prediction. The video encoder 200 and the video decoder 300 may also support asymmetric partitioning for PU sizes of 2N×nU, 2N×nD, nL×2N, and nR×2N for inter prediction.

[0257]

[0263] In examples where the mode select unit 202 does not further partition the CUs into PUs, each CU may be associated with a luma coding block and a corresponding chroma coding block. As above, the size of a CU may refer to the size of the luma coding block of the CU. The video encoder 200 and the video decoder 300 may support CU sizes of 2N×2N, 2N×N, or N×2N.

[0258]

[0264] For other video coding techniques, such as intra block copy mode coding, affine mode coding, and linear model (LM) mode coding, as some examples, the mode select unit 202 generates a predictive block for the current block being coded via a respective unit associated with the coding technique. In some examples, such as palette mode coding, the mode select unit 202 may not generate a predictive block, but instead generate syntax elements that indicate a scheme for reconstructing the block based on a selected palette. In such modes, the mode select unit 202 may provide these syntax elements to the entropy coding unit 220 to be coded.

[0259]

[0265] As described above, the residual generation unit 204 receives the video data for a current block and a corresponding predictive block. The residual generation unit 204 then generates a residual block for the current block. To generate the residual block, the residual generation unit 204 calculates the sample-by-sample difference between the predictive block and the current block.

[0260]

[0266] 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 the 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, e.g., a linear transform and a secondary transform, such as a rotation transform, on the residual block. In some examples, transform processing unit 206 does not apply a transform to the residual block.

[0261]

[0267] When operating according to AV1, transform processing unit 206 may apply one or more transforms to the residual block to generate a block of transform coefficients (referred to herein as a "transform coefficient block"). Transform processing unit 206 may apply various transforms to the residual block to form the transform coefficient block. For example, transform processing unit 206 may apply a horizontal / vertical transform combination that may include a discrete cosine transform (DCT), an asymmetric discrete sine transform (ADST), an inverse ADST (e.g., ADST in reverse order), and an identity transform (IDTX). When using an identity transform, the transform is skipped in one of the vertical or horizontal directions. In some examples, the transform process may be skipped.

[0262]

[0268] The quantization unit 208 may quantize the transform coefficients in the transform coefficient block to generate a quantized transform coefficient block. The quantization unit 208 may quantize the transform coefficients of the transform coefficient block according to a quantization parameter (QP) value associated with the current block. The video encoder 200 (e.g., via the mode selection unit 202) may adjust the degree of quantization applied to the transform coefficient block associated with the current block by adjusting the QP value associated with the CU. Quantization may result in loss of information, and thus the quantized transform coefficients may be less accurate than the original transform coefficients generated by the transform processing unit 206.

[0263]

[0269] 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. Reconstruction unit 214 may generate a reconstructed block that corresponds to the current block (possibly with some distortion) based on the reconstructed residual block and the predictive block generated by mode selection unit 202. 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 the reconstructed block.

[0264]

[0270] Filter unit 216 may perform one or more filter operations on the reconstructed block. For example, filter unit 216 may perform a deblocking operation to reduce blockiness artifacts along the edges of a CU. The operations of filter unit 216 may be skipped in some examples.

[0265]

[0271] When operating according to AV1, filter unit 216 may perform one or more filter operations on the reconstructed block. For example, filter unit 216 may perform a deblocking operation to reduce blockiness artifacts along the edges of a CU. In another example, filter unit 216 may apply a constrained directional enhancement filter (CDEF), which may be applied after deblocking, and may include application of a non-separable, nonlinear, low-pass directional filter based on the estimated edge direction. Filter unit 216 may also include a loop restoration filter, which may be applied after the CDEF and may include a separable symmetric normalized Wiener filter or a dual autoinduction filter.

[0266]

[0272] Video encoder 200 stores the reconstructed blocks in DPB 218. For example, in examples where the operations of filter unit 216 are not performed, reconstruction unit 214 may store the reconstructed blocks in DPB 218. In examples where the operations of filter unit 216 are performed, filter unit 216 may store the filtered reconstructed blocks in DPB 218. Motion estimation unit 222 and motion compensation unit 224 may retrieve reference pictures formed from the reconstructed (and potentially filtered) blocks from DPB 218 to inter predict blocks of a later-encoded picture. In addition, 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.

[0267]

[0273] In general, the entropy encoding unit 220 may entropy encode syntax elements received from other functional components of the video encoder 200. For example, the entropy encoding unit 220 may entropy encode quantized transform coefficient blocks from the quantization unit 208. As another example, the entropy encoding unit 220 may entropy encode predictive syntax elements (e.g., motion information for inter prediction or intra mode information for intra prediction) from the mode selection unit 202. The entropy encoding unit 220 may perform one or more entropy encoding operations on syntax elements, which 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-length-to-variable-length (V2V) coding operation, a syntax-based context-adaptive binary arithmetic coding (SBAC) operation, a probability interval partitioned entropy (PIPE) coding operation, an exponential-Golomb coding operation, or another type of entropy coding operation on the data. In some examples, entropy encoding unit 220 may operate in a bypass mode in which syntax elements are not entropy coded.

[0268]

[0274] The video encoder 200 may output a bitstream that includes entropy coding syntax elements needed to reconstruct blocks of a slice or picture. In particular, the entropy coding unit 220 may output the bitstream.

[0269]

[0275] According to AV1, entropy encoding unit 220 may be configured as a symbol-to-symbol adaptive multi-symbol arithmetic coder. Syntax elements in AV1 include an alphabet of N elements, and a context (e.g., a probability model) includes a set of N probabilities. Entropy encoding unit 220 may store the probabilities as n-bit (e.g., 15-bit) cumulative distribution functions (CDFs). Entropy encoding unit 22 may perform recursive scaling with an update factor based on the alphabet size to update the context.

[0270]

[0276] The operations described above are described with respect to blocks. Such descriptions should be understood as being operations for a luma coding block and / or a chroma coding block. As described above, in some examples, the luma coding block and the chroma coding block are the luma component and the chroma component of a CU. In some examples, the luma coding block and the chroma coding block are the luma component and the chroma component of a PU.

[0271]

[0277] In some examples, operations performed with respect to luma coding blocks need not be repeated for chroma coding blocks. As one example, operations to identify motion vectors (MVs) and reference pictures for luma coding blocks need not be repeated to identify MVs and reference pictures for chroma blocks. Rather, MVs for luma coding blocks may be scaled to determine MVs for chroma blocks, and the reference pictures may be the same. As another example, the intra prediction process may be the same for luma coding blocks and chroma coding blocks.

[0272]

[0278] Video encoder 200 represents an example of a device configured to encode video data, the device including a memory configured to store video data, and one or more processing units implemented in a circuit and configured to access from the memory a mapping table in which two or more geometric partitioning mode (GEO) partition modes are grouped together such that they have the same index value in the mapping table, where the number of GEO partition modes is equal to M and the number of partition modes in each group of two or more GEO partition modes is equal to K, where K is less than M. Video encoder 200 may be configured to determine, from the mapping table, one partition mode of the plurality of partition modes, and signal an index into the mapping table indicating the partition mode for decoding a current block of video data.

[0273]

[0279] In some examples, the video encoder 200 may be configured to determine costs associated with one or more partition modes of a geometric partitioning mode (GEO), where there are M partition modes of GEO, build a mapping table (e.g., a mapping list) having index values ​​indicating the respective partition modes based on the respective costs for the one or more partition modes of GEO, determine one partition mode among the multiple partition modes based on the mapping table, and signal an index to the mapping table indicating the partition mode for decoding a current block of video data.

[0274]

[0280] 3 is a block diagram illustrating an example video decoder 300 capable of performing techniques of this disclosure. FIG. 3 is provided for purposes of illustration and is not intended to limit the techniques as broadly illustrated and described in this disclosure. For purposes of illustration, 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.

[0275]

[0281] In the embodiment of FIG. 3, the video decoder 300 includes a coded picture buffer (CPB) memory 320, an entropy decoding unit 302, a prediction processing unit 304, an inverse quantization unit 306, an inverse transform processing unit 308, a reconstruction unit 310, a filter unit 312, and a decoded picture buffer (DPB) 314. Any or all of the CPB memory 320, the entropy decoding unit 302, the prediction processing unit 304, the inverse quantization unit 306, the inverse transform processing unit 308, the reconstruction unit 310, the filter unit 312, and the DPB 314 may be implemented in one or more processors or processing circuits. For example, the units of the video decoder 300 may be implemented as one or more circuits or logic elements as part of a hardware circuit, or as part of a processor, ASIC, or FPGA. Moreover, the video decoder 300 may include additional or alternative processors or processing circuitry for performing these and other functions.

[0276]

[0282] 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 prediction 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.

[0277]

[0283] When operating according to AV1, the compensation unit 316 may be configured to decode coding blocks of the video data (e.g., both luma coding blocks and chroma coding blocks) using translational motion compensation, affine motion compensation, OBMC, and / or synthetic inter-intra prediction, as described above. The intra prediction unit 318 may be configured to decode coding blocks of the video data (e.g., both luma coding blocks and chroma coding blocks) using directional intra prediction, non-directional intra prediction, recursive filter intra prediction, CFL, intra block copy (IBC), and / or color palette mode, as described above.

[0278]

[0284] The CPB memory 320 may store video data, such as an encoded video bitstream, to be decoded by components of the video decoder 300. The video data stored in the CPB memory 320 may be obtained, for example, from the computer-readable medium 110 (FIG. 1). The CPB memory 320 may include a CPB that stores encoded video data (e.g., syntax elements) from the encoded video bitstream. The CPB memory 320 may also store video data other than syntax elements of coded pictures, such as temporary data representing output from various units of the video decoder 300. The DPB 314 generally stores decoded pictures that the video decoder 300 may output and / or use as reference video data when decoding subsequent data or pictures of the encoded video bitstream. The CPB memory 320 and the DPB 314 may be formed by any of a variety of memory devices, such as DRAM, including SDRAM, MRAM, RRAM, or other types of memory devices. The CPB memory 320 and the DPB 314 may be provided by the same memory device or by separate memory devices. In various examples, the CPB memory 320 may be on-chip with other components of the video decoder 300 or may be off-chip relative to those components.

[0279]

[0285] 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 such as those discussed above for 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.

[0280]

[0286] The various units shown in FIG. 3 are presented to aid in understanding the operations performed by the video decoder 300. The units may be implemented as fixed function circuits, programmable circuits, or a combination thereof. As with FIG. 2, fixed function circuits refer to circuits that provide a particular function and are predefined in the operations they can perform. Programmable circuits refer to circuits that can be programmed to perform a variety of tasks and provide flexible functionality in the operations they can perform. 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 a fixed function circuit may execute software instructions (e.g., to receive parameters or output parameters), the types of operations that the fixed function circuit performs are generally immutable. In some examples, one or more of the units may be separate circuit blocks (fixed function or programmable), and in some examples, one or more of the units may be integrated circuits.

[0281]

[0287] The video decoder 300 may include a programmable core formed from ALUs, EFUs, digital circuits, analog circuits, and / or programmable circuits. In examples in which the operations of the video decoder 300 are performed by software executing on programmable circuits, on-chip or off-chip memory may store instructions (e.g., object code) of the software that the video decoder 300 receives and executes.

[0282]

[0288] The entropy decoding unit 302 may receive the encoded video data from the CPB and entropy decode the video data to recover the syntax elements. The prediction processing unit 304, the inverse quantization unit 306, the inverse transform processing unit 308, the reconstruction unit 310, and the filter unit 312 may generate decoded video data based on the syntax elements extracted from the bitstream.

[0283]

[0289] In general, the video decoder 300 reconstructs a picture on a block-by-block basis. The video decoder 300 may perform a reconstruction operation on each block individually (here, the block currently being reconstructed, i.e., decoded, may be referred to as the “current block”).

[0284]

[0290] The entropy decoding unit 302 may entropy decode syntax elements that specify the quantized transform coefficients of the quantized transform coefficient block as well as transform information such as a quantization parameter (QP) and / or a transform mode indication(s). The inverse quantization unit 306 may use the QP associated with the quantized transform coefficient block to determine the degree of quantization, and similarly the degree of inverse quantization that the inverse quantization unit 306 should apply. The inverse quantization unit 306 may, for example, perform a bitwise left shift operation to inverse quantize the quantized transform coefficients. The inverse quantization unit 306 may thereby form a transform coefficient block including the transform coefficients.

[0285]

[0291] After the inverse quantization unit 306 forms the transform coefficient blocks, the inverse transform processing unit 308 may apply one or more inverse transforms to the transform coefficient blocks to generate a residual block related to the current block. For example, the inverse transform processing unit 308 may apply an inverse DCT, an inverse integer transform, an inverse Karhunen-Loeve transform (KLT), an inverse rotational transform, an inverse transform, or another inverse transform to the transform coefficient blocks.

[0286]

[0292] Further, prediction processing unit 304 generates a prediction block according to the prediction information syntax element entropy decoded by entropy decoding unit 302. For example, if the prediction information syntax element indicates that the current block is inter predicted, motion compensation unit 316 may generate a prediction block. In this case, the prediction information syntax element may indicate a reference picture in DPB 314 from which to retrieve a reference block, as well as a motion vector that specifies 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 an inter prediction process in a manner substantially similar to that described with respect to motion compensation unit 224 (FIG. 2).

[0287]

[0293] As another example, if the prediction information syntax element indicates that the current block is intra predicted, the intra prediction unit 318 may generate a prediction block according to the intra prediction mode indicated by the prediction information syntax element. Again, the intra prediction unit 318 may generally perform an intra prediction process in a manner substantially similar to that described with respect to the intra prediction unit 226 (FIG. 2). The intra prediction unit 318 may retrieve data of samples neighboring the current block from the DPB 314.

[0288]

[0294] The reconstruction unit 310 may reconstruct the current block using the predictive block and the residual block. For example, the reconstruction unit 310 may add samples of the residual block to corresponding samples of the predictive block to reconstruct the current block.

[0289]

[0295] Filter unit 312 may perform one or more filter operations on the reconstructed block. For example, filter unit 312 may perform a deblocking operation to reduce blockiness artifacts along edges of the reconstructed block. In all examples, the operations of filter unit 312 may not necessarily be performed.

[0290]

[0296] The video decoder 300 may store the reconstructed blocks in the DPB 314. For example, in examples where the operation of the filter unit 312 is not required, the reconstruction unit 310 may store the reconstructed blocks in the DPB 314. In examples where the operation of the filter unit 312 is performed, the filter unit 312 may store the filtered reconstructed blocks in the DPB 314. As described above, the DPB 314 may provide reference information to the prediction processing unit 304, such as samples of the current picture for intra prediction and previously decoded pictures for subsequent motion compensation. Additionally, the video decoder 300 may output decoded pictures (e.g., decoded video) from the DPB 314 for later presentation on a display device, such as the display device 118 of FIG. 1.

[0291]

[0297] In this manner, video decoder 300 represents one example of a video decoding device including a memory configured to store video data and one or more processing units implemented in a circuit and configured to access from the memory a mapping table in which two or more geometric partitioning mode (GEO) partition modes are grouped together such that they have the same index value in the mapping table, where the number of GEO partition modes is equal to M and the number of partition modes in each group of two or more GEO partition modes is equal to K, where K is less than M. Video decoder 300 may be configured to determine a partition mode among the multiple partition modes from the mapping table and reconstruct a current block of video data based on the partition mode (e.g., the determined partition mode).

[0292]

[0298] In some examples, the video decoder 300 may be configured to determine a cost associated with one or more partition modes of a geometric partitioning mode (GEO) where there are M partition modes of GEO, construct a mapping table (e.g., a mapping list) having index values ​​indicating the respective partition modes based on the respective TM costs for the one or more partition modes of GEO, determine one partition mode among the multiple partition modes based on the mapping table, and reconstruct a current block of video data based on the partition mode (e.g., the determined partition mode).

[0293]

[0299] 12 is a flowchart illustrating an example method of decoding according to an example technique described in this disclosure. The example technique is described with respect to memory, examples of which include memory 120, CPB memory 320, DPB 314, or other memory accessible by video decoder 300. The example technique is also described with respect to processing circuitry, examples of which include video decoder 300, or a unit of video decoder 300, such as prediction processing unit 304, motion compensation unit 316, or any other unit of video decoder 300.

[0294]

[0300] Also, for ease of explanation, reference is made to Figures 6, 10A-10D, and 11. For example, a memory may be configured to store video data of a current block 1000. A processing circuit coupled to the memory may be configured to perform the example technique of Figure 12.

[0295]

[0301] As an example, the processing circuit may determine (1200) that the geometric partitioning mode is enabled for a current block of video data 1000. For example, the processing circuit may receive one or more syntax elements from a bitstream encoded by the video encoder 200 that defines a coding mode and includes information that the coding mode is a geometric partitioning mode. The processing circuit may determine that a partitioning mode is enabled for the current block 1000 based on the received one or more syntax elements. Examples of geometric partitioning modes include GEO mode, GEO+MMVD mode, and GEO+TM mode. The term GEO is used interchangeably with GPM (geometric partitioning mode).

[0296]

[0302] The geometric partitioning modes include multiple partitioning modes, each of which defines an edge for partitioning. For example, Figure 6 shows an example of different partitioning modes, each of which defines a respective edge used to partition a block into two partitions.

[0297]

[0303] For each partitioning mode among at least two (e.g., a subset or all of the partitioning modes) of the plurality of partitioning modes, the processing circuitry may be configured to determine a respective cost associated with the respective partitioning mode (1202). For example, the processing circuitry may repeatedly perform the operation of determining a cost for the current (e.g., each) partitioning mode (1100) of FIG. 11 and the operation of setting the next partitioning mode to the current partitioning mode (1104) of FIG. 11 until there are no more partitioning modes in FIG. 11 to evaluate ("NO" in 1102). The number of partitioning modes evaluated may be all available partitioning modes or a subset of the available partitioning modes.

[0298]

[0304] As an example, to determine the respective costs associated with each partition mode, the processing circuitry may be configured to determine a respective reference template based on the respective partition mode of the plurality of partition modes, and to determine a current template 1004 for the current block 1000, as shown in Figure 10A. As described, the current template 1004 includes samples outside the current block 1000, such as samples from the top portion 1006A and samples from the left portion 1006B, as shown in Figure 10A. The processing circuitry may determine the respective costs associated with each partition mode based on the respective reference template and the current template 1004.

[0299]

[0305] As described above, the processing circuitry may be configured to determine the respective reference templates. An example of the respective reference templates is the reference template 1022 of FIG. 10D. In some examples, to determine the respective reference templates, the processing circuitry may be configured to determine a first reference template 1014A based on a first reference block 1010A of FIG. 10B and FIG. 10C that is identified by a first motion vector 1012A of FIG. 10B of a first partition 1002A of FIG. 10A and FIG. 10B of the current block 1000. The processing circuitry may be configured to determine a second reference template 1014B based on a second reference block 1010B of FIG. 10B and FIG. 10C that is identified by a second motion vector 1012B of FIG. 10B of a second partition 1002B of FIG. 10A and FIG. 10B of the current block 1000.

[0300]

[0306] The first reference template 1014A includes a first portion of samples above the first reference block 1010A and a second portion of samples to the left of the first reference block 1010A. The second reference template 1014B includes a first portion of samples above the second reference block 1010B and a second portion of samples to the left of the second reference block 1010B.

[0301]

[0307] The processing circuitry may be configured to combine samples from the first reference template 1014A and samples from the second reference template 1014B based on the respective partitioning modes to generate a reference template (e.g., reference template 1022) based on the respective partitioning modes. That is, each of the respective partitioning modes may define which samples from the first reference template 1014A and the second reference template 1014B are used, and the processing circuitry may then combine the samples, possibly using blending, but not necessarily using blending.

[0302]

[0308] As an example, the processing circuitry may be configured to apply respective partitioning modes to the first reference block 1010A to combine samples from the first reference template 1014A and samples from the second reference template 1014B based on the respective partitioning modes to generate the respective reference templates. For example, as shown in FIG. 10C, the processing circuitry may apply a partitioning mode that defines an edge 1008 of the multiple partitioning modes to the first reference block 1010A.

[0303]

[0309] The processing circuitry can extend each applied division mode into samples of the first reference template 1014A. For example, as shown in FIG. 10C, the processing circuitry can extend the edge 1008 to form a line 1016A that extends into samples of the first reference template 1014A to partition the first reference template 1014A into a first portion including the first set of samples 1018A and a second portion including the second set of samples 1018B.

[0304]

[0310] The processing circuitry may access the first set 1018A of samples in the first reference template 1014A based on the extension of the applied respective division mode to the samples of the first reference template 1014A. For example, as shown in FIG. 10C, the processing circuitry may access one or more samples in the first set 1018A of samples. The first reference block 1010A is based on the first partition 1002A, which is located relative to the edge 1008 in the same direction as the portion including the first set 1018A of samples is located relative to the line 1016A. Thus, the first set 1018A of samples in the first reference template 1014A may be one or more samples including all of the first portion.

[0305]

[0311] 10C, the processing circuitry may apply each of the partitioning modes to the second reference block 1010B as well. For example, the processing circuitry may apply a partitioning mode that is one of the partitioning modes that defines the edge 1008 to the second reference block 1010B.

[0306]

[0312] The processing circuitry may extend each applied partitioning mode into samples of the second reference template 1014B. For example, as shown in FIG. 10C, the processing circuitry extends the edge 1008 to form a line 1016B that extends into samples of the second reference template 1014B to partition the second reference template 1014B into a first portion including the fourth sample set 1020A and a second portion including the third sample set 1020B.

[0307]

[0313] The processing circuitry may access a respective third set 1020B of samples in the second reference template 1014B based on the extension of the respective division mode applied to the samples of the second reference template 1014B. For example, as shown in FIG. 10C, the processing circuitry may access one or more samples in the third set 1020B of samples. The second reference block 1010B is based on the second partition 1002B, which is disposed relative to the edge 1008 in the same direction as the portion containing one-third of the samples 1020B is disposed relative to the line 1016B. Thus, the third set 1020B of samples in the second reference template 1014B may be one or more samples containing all of the third set 1020B of samples.

[0308]

[0314] The processing circuitry may combine the respective first set 1018A and the respective third set 1020B of samples to generate the respective reference template 1022. For example, as shown in FIG. 10D, the processing circuitry may combine samples of the first set 1018A and samples of the third set 1020B along a line 1016C corresponding to lines 1016A, 1016B to generate the reference template 1022. In some examples, the processing circuitry may blend one or more samples in the respective first set 1018A of samples and the fourth set 1020A of samples, blend one or more samples in the respective second set 1020B of samples and the second set 1018B of samples, and combine the respective first set 1018A of samples and the respective third set 1020B of samples based on the blending. However, such blending is not required in all embodiments.

[0309]

[0315] Referring again to FIG. 12, the processing circuit may build a mapping list including index values ​​respectively associated with values ​​indicative of the respective splitting modes based on the respective costs associated with the respective splitting modes, with a lower index value in the mapping list being associated with a first splitting mode having a lower cost than a second splitting mode having a higher index value in the mapping list (1204). For example, after or in conjunction with determining the respective costs, as described above with respect to FIG. 11, the processing circuit may build the mapping list. As an example, the processing circuit may order one or more of the splitting modes in ascending order based on the respective costs. In some examples, the processing circuit may include the N (e.g., 32) splitting modes with the lowest costs in the mapping list.

[0310]

[0316] Also, as described above, the mapping list may include index values ​​(e.g., index values ​​in ascending order starting from 0). Each of the index values ​​represents an entry in the mapping list, and each entry in the mapping list may store a value indicative of a splitting mode. For example, an index value of 0 in the mapping list may point to a first entry in the mapping list, which may store a first value indicative of a first splitting mode. An index value of 1 in the mapping list may point to a second entry in the mapping list, which may store a second value indicative of a second splitting mode, and so on. Thus, the mapping list includes index values ​​each associated with a value indicative of a respective splitting mode.

[0311]

[0317] In one or more examples, a lower index value in the mapping list is associated with a first partitioning mode having a lower cost than a second partitioning mode having a higher index value in the mapping list. For example, as described above, a first value indicating the first partitioning mode may be stored in an entry in the mapping list identified by an index value of 0, while a second value indicating the second partitioning mode may be stored in an entry in the mapping list identified by an index value of 1. In this example, the first cost of the first partitioning mode is less than the second cost of the second partitioning mode.

[0312]

[0318] The mapping list includes a value indicative of a split mode. The value indicative of a split mode may be a split index value, such as a value formed as an index into Table 1. For example, assume that a first entry in the mapping list (e.g., index 0) includes a value of 10 and a second entry in the mapping list (e.g., index 1) includes a value of 5. In this example, the value 10 stored in the first entry of the mapping list refers to an edge having an angle of 4 and an offset of 0 according to Table 1. The value of 5 stored in the second entry of the mapping list refers to an edge having an angle of 2 and an offset of 3 according to Table 1.

[0313]

[0319] The processing circuit may determine a partition mode among a plurality of partition modes in (e.g., based on) the mapping list (1206). As an example, the processing circuit may receive an index value into the mapping list (e.g., based on information signaled by the video encoder 200). In some examples, the processing circuit may fixed-length binary decode information indicative of the index value, truncated binary decode information indicative of the index value, Golomb-Rice decode information indicative of the index value, or context-based adaptive coding (CABAC) decode one or more bins of information indicative of the index value.

[0314]

[0320] For example, in some examples, the processing circuit may CABAC decode all bins of the information indicative of the index. In some examples, the processing circuit may CABAC decode some of the bins of the information indicative of the index, while other bins may be bypass decoded. In some examples, earlier bins may be CABAC decoded, while later bins may be bypass decoded.

[0315]

[0321] The processing circuitry may determine the split mode based on the index value into the mapping list. For example, continuing with the above example, assume that the index into the mapping list is index 0. In this example, the processing circuitry may determine that the split mode value is split mode 10. The processing circuitry may use split mode 10 as an index into Table 1 and determine, according to Table 1, that the edge for partitioning the current block 1000 is angle 4, offset 0.

[0316]

[0322] The processing circuit may reconstruct 1208 the current block of video data 1000 based on the partition mode (e.g., the determined partition mode). For example, the processing circuit may partition the current block 1000 according to edges defined by the determined partition mode. For example, the processing circuit may partition the current block 1000 into a first partition 1002A and a second partition 1002B.

[0317]

[0323] The processing circuit may determine a first set of predicted values ​​for the first partition 1002A of the current block 1000 defined by the determined partition mode. For example, the first set of predicted values ​​may be values ​​in the first reference block 1010A for an edge 1008 in the same direction as the first partition 1002A.

[0318]

[0324] The processing circuit may determine a second set of predicted values ​​for the second partition 1002B of the current block 1000 defined by the determined partition mode. For example, the second set of predicted values ​​may be values ​​in a second reference block 1010B for an edge 1008 in the same direction as the second partition 1002B.

[0319]

[0325] The processing circuitry may also determine a residual value of the current block 1000. For example, the processing circuitry may receive information indicative of a residual value, where the residual value indicates a difference between the predicted block and the current block 1000.

[0320]

[0326] The processing circuitry may reconstruct the current block 1000 based on the first set of predictors, the second set of predictors, and the residual value. For example, the processing circuitry may generate a predictive block based on the first set of predictors and the second set of predictors, possibly including blending one or more predictive values ​​from the first set of predictors with one or more predictive values ​​from the second set of predictors. The processing circuitry may add the predictive block and the residual value to reconstruct the current block.

[0321]

[0327] 13 is a flowchart illustrating an example method of encoding according to an example technique described in this disclosure. The example technique is described with respect to memory, examples of which include memory 106, video data memory 230, decoded picture buffer 218, or other memory accessible by video encoder 200. The example technique is also described with respect to processing circuitry, examples of which include video encoder 200 or a unit of video encoder 200, such as mode selection unit 202, motion estimation unit 222, motion compensation unit 224, or any other unit of video encoder 200.

[0322]

[0328] The processing circuit may be configured to determine 1300 that a geometric partitioning mode is enabled for the current block 1000. For example, the processing circuit may attempt to encode the current block 1000 using different coding modes and determine that the geometric partitioning mode is the coding mode that provides efficient coding. Examples of geometric partitioning modes include GEO mode, GEO+MMVD mode, and GEO+TM mode. The term GEO is used interchangeably with GPM (geometric partitioning mode).

[0323]

[0329] For each partition mode among at least two (e.g., a subset or all of the partition modes) of the plurality of partition modes, the processing circuit may determine a respective cost associated with the respective partition mode (1302) and construct a mapping list having a value indicative of the partition mode based on the respective cost associated with the respective partition mode (1304). For example, the processing circuit may perform operations similar to those described above in FIG. 12, but from the perspective of the video encoder 200. For example, the processing circuit may construct a mapping list including index values ​​respectively associated with values ​​indicative of the respective partition modes based on the respective costs associated with the respective partition modes, with a lower index value in the mapping list being associated with a first partition mode having a lower cost than a second partition mode having a higher index value in the mapping list. In this manner, the mapping list constructed by the video encoder 200 and the mapping list constructed by the video decoder 300 are the same.

[0324]

[0330] The processing circuitry may determine which of the multiple partitioning modes to include in the mapping list (1306). For example, the processing circuitry may determine a particular partitioning mode that provides a desired coding efficiency and determine a position of the particular partitioning mode in the mapping list. Based on the position of the particular partitioning mode in the mapping list, the processing circuitry may determine an index for the mapping list.

[0325]

[0331] The processing circuitry may signal the index to a mapping list for the partitioning mode (e.g., the determined partitioning mode) 1308. For example, the processing circuitry may fixed-length binary encode the information indicative of the index, truncated binary encode the information indicative of the index, Golomb-Rice encode the information indicative of the index, or context-based adaptive coding (CABAC) encode one or more bins of the information indicative of the index.

[0326]

[0332] The processing circuitry may also signal information indicating a residual value between the predictive block generated based on the partition mode and the current block 1000. Based on an index into the mapping list, the video decoder 300 may generate a predictive block and add the predictive block to the residual value to reconstruct the current block 1000.

[0327]

[0333] The examples of Figures 12 and 13 may be considered as methods of encoding or decoding video data. For example, the video encoder 200 and the video decoder 300 may determine that a geometric partitioning mode is enabled for a current block of video data (1300 in Figure 13, 1200 in Figure 12). For each partition mode among at least one of the partition modes, the video encoder 200 and the video decoder 300 may determine a respective cost associated with the respective partition mode (1302 in Figure 13, 1202 in Figure 12). The video encoder 200 and the video decoder 300 may construct a mapping list having a value indicating the partition mode based on the respective cost associated with the respective partition mode (1304 in Figure 13, 1204 in Figure 12). The video encoder 200 and the video decoder 300 may determine the partition modes to be included in the mapping list (1306 in Figure 13, and 1206 in Figure 12).

[0328]

[0334] In one or more examples, both the video encoder 200 and the video decoder 300 may be configured to reconstruct the current block based on the partition mode. For example, the video decoder 300 may reconstruct the current block for display. The video encoder 200 may also reconstruct the current block as part of a feedback loop of the inverse quantization unit 210, the inverse transform processing unit 212, and the reconstruction unit 214. In this manner, Figures 12 and 13 show a method of encoding or decoding video data. The video encoder 200 may also be configured to signal an index (e.g., an index into a mapping list) that indicates the partition mode.

[0329]

[0335] 14 is a flowchart illustrating an example method of decoding video data with reference picture resampling. In the example of FIG. 14, the processing circuitry of the video decoder 300 may determine (1400) that a geometric partitioning mode is enabled for a block of a picture. Examples of the geometric partitioning modes include a GEO mode, a GEO+MMVD mode, and a GEO+TM mode. The term GEO is used interchangeably with GPM (geometric partitioning mode).

[0330]

[0336] The processing circuit may determine the size(s) of the reference picture(s) for the block (1402). For example, in a geometric partition mode, there may be two partitions, but for each of the two partitions, there may be a motion vector that points to a reference block in the reference picture. Thus, there may be two reference pictures, i.e., a first reference picture for the first partition of the two partitions and a second reference picture for the second partition of the two partitions.

[0331]

[0337] There may be a size associated with the first reference picture and the second reference picture. As an example, the size may refer to the number of samples in the reference picture. The number of samples in the reference picture may include samples that have no luma or chroma values ​​(e.g., blank samples or black samples). For example, the size of the reference picture(s) may be based on reference picture resampling (RPR). The first reference picture and the second reference picture may be larger, smaller, or the same size as the picture that contains the block being decoded.

[0332]

[0338] The processing circuit may determine whether the size of the picture is the same as the size of the reference picture(s) (1404). If the size of the picture is the same as the size of the reference picture(s) ("Yes" at 1404), the processing circuit may perform a split mode reordering process (1406). Examples of the split mode reordering process include example techniques described in this disclosure in which the video decoder 300 builds a mapping list based on the respective costs of the respective split modes, as described in this disclosure, such as the example techniques for building a mapping list described in FIG. 11 and FIG. 12.

[0333]

[0339] If the size of the picture is not the same as the size of at least one reference picture ("NO" at 1404), the processing circuit may bypass the partition mode reordering process (1408). For example, rather than building a mapping list based on the respective costs of each partition mode, the processing circuit may utilize a default ordering of the partition modes. That is, there may be no reordering of indexes for the partition modes, and the mapping list may be in a default ordering. The default ordering may be a default order (e.g., from smaller partition mode index to larger partition mode index) for all candidates for GEO mode, GEO+MMVD mode, and GEO+TM mode.

[0334]

[0340] In this manner, there may be restrictions for partition mode reordering based on whether the reference picture has the same size as the current picture (e.g., in reference picture resampling (RPR), etc.) or has a different size. For example, according to the example of FIG. 14, the processing circuit may determine that the geometric partitioning mode is enabled for the first block of the first picture and determine that the size of the reference picture(s) is the same as the size of the first picture. In this example, the processing circuit may perform a partition mode reordering process (e.g., as in the examples of FIG. 11 and FIG. 12, and throughout this disclosure).

[0335]

[0341] According to the example of Figure 14, the processing circuit may determine that the geometric partitioning mode is enabled for the second block of the second picture and determine that the size of at least one reference picture is different from the size of the second picture (e.g., in the RPR). In this example, the processing circuit may bypass the partition mode reordering process based on the determination that the size of the at least one reference picture is different from the size of the second picture.

[0336]

[0342] This disclosure describes several example techniques, which may be implemented together or separately.

[0337]

[0343] Clause 1. A method for decoding video data, comprising: accessing a mapping table from a memory, wherein two or more geometric partitioning mode (GEO) partition modes are grouped together to have the same index value in the mapping table, the number of GEO partition modes being equal to M, the number of partition modes in each group of two or more GEO partition modes being equal to K, and K being less than M; determining a partition mode from the mapping table; and reconstructing a current block of the video data based on the determined partition mode.

[0338]

[0344] Clause 2. The method of clause 1, wherein the two or more GEO modes are grouped together based on two or more GEO split modes having the same offset index and an approximately perpendicular angle to each other.

[0339]

[0345] Clause 3. The method of clause 1, wherein determining the partitioning mode includes fixed-length decoding a group index value in the range of 0 to M / (K-1), and determining the partitioning mode based on the group index value.

[0340]

[0346] Clause 4. The method of clause 1, wherein determining the partitioning mode includes Golomb-Rice decoding the group index value using a divisor D, the group index value being in the range of 0 to M / (K-1) and D being in the range of 1 to M / K.

[0341]

[0347] Clause 5. The method of any one of clauses 1 to 4, wherein the group of two or more GEO partition modes includes K partition modes, and each of the K partition modes in the group is assigned a respective submode index value.

[0342]

[0348] Clause 6. The method of clause 5, wherein determining the partition mode includes parsing a submode index, which is encoded using fixed-length binary coding or Golomb-Rice coding, to identify one of K partition modes in the group, and determining the partition mode based on the identified one of the K partition modes.

[0343]

[0349] Clause 7. The method of clause 5, wherein determining the partition mode includes determining a sub-mode index value of one of the K partition modes in the group based on a template matching (TM) cost to identify one of the K partition modes in the group, and determining the partition mode based on the identified one of the K partition modes.

[0344]

[0350] Clause 8. The method of clause 5, further comprising ordering the K partitioning modes in the group based on a template matching (TM) cost associated with each of the K partitioning modes in the group.

[0345]

[0351] Clause 9. A method as described in any of clauses 1 to 8, wherein reconstructing the current block based on the determined partition mode includes determining a first set of predicted values ​​for a first partition of the current block defined by the determined partition mode, determining a second set of predicted values ​​for a second partition of the current block defined by the determined partition mode, determining residual values ​​for the current block, and reconstructing the current block based on the first set of predicted values, the second set of predicted values, and the residual values.

[0346]

[0352] Clause 10. A method for encoding video data, comprising: accessing a mapping table from a memory, where two or more geometric partition mode (GEO) partition modes are grouped together such that they have the same index value in the mapping table, where the number of GEO partition modes is equal to M, and the number of partition modes in each group of two or more GEO partition modes is equal to K, where K is less than M; determining a partition mode from the mapping table; and signaling an index to the mapping table indicating the partition mode for decoding a current block of video data.

[0347]

[0353] Clause 11. The method of clause 10, wherein the two or more GEO modes are grouped based on two or more GEO split modes having the same offset index and an approximately perpendicular angle to each other.

[0348]

[0354] Clause 12. The method of clause 10, wherein signaling the index includes fixed-length encoding a group index value, indicative of the group, within a range of 0 to M / (K-1).

[0349]

[0355] Clause 13. The method of clause 10, wherein signaling the index includes Golomb-Rice encoding a group index value indicating the group with a divisor D, the group index value being in the range of 0 to M / (K-1), and D being in the range of 1 to M / K.

[0350]

[0356] Clause 14. The method of any of clauses 10 to 13, wherein the group of two or more GEO partition modes includes K partition modes, and each of the K partition modes in the group is assigned a respective submode index value.

[0351]

[0357] Clause 15. The method of clause 14, further comprising signaling a submode index that is coded using fixed length binary coding or Golomb-Rice coding to identify one of the K partitioning modes in the group.

[0352]

[0358] Clause 16. The method of clause 14, further comprising determining a submode index value for one of the K partition modes in the group based on a template matching (TM) cost to identify one of the K partition modes in the group.

[0353]

[0359] Clause 17. The method of clause 14, further comprising ordering the K partitioning modes in the group based on a template matching (TM) cost associated with each of the K partitioning modes in the group.

[0354]

[0360] Clause 18. A device for decoding video data, comprising: a memory; and a processing circuit coupled to the memory and configured to perform the method according to any one of clauses 1 to 9.

[0355]

[0361] Clause 19. The device of clause 18, further comprising a display configured to display the decoded video data.

[0356]

[0362] Clause 20. A device according to any of clauses 18 and 19, wherein the device comprises one or more of a camera, a computer, a mobile device, a broadcast receiver device, or a set-top box.

[0357]

[0363] Clause 21. A computer-readable storage medium storing instructions that, when executed, cause one or more processors to perform the method of any of clauses 1 to 9.

[0358]

[0364] Clause 22. A device for decoding video data, comprising means for performing the method according to any of clauses 1 to 9.

[0359]

[0365] Clause 23. A device for encoding video data, comprising a memory and a processing circuit configured to perform the method according to any of clauses 10 to 17.

[0360]

[0366] Clause 24. The device of clause 23, further comprising a camera configured to capture video data.

[0361]

[0367] Clause 25. A computer-readable storage medium storing instructions that, when executed, cause one or more processors to perform the method of any of clauses 10 to 17.

[0362]

[0368] Clause 26. A device for encoding video data, comprising means for performing the method according to any of clauses 10 to 17.

[0363]

[0369] Clause 27. A method for decoding video data, comprising: determining a cost associated with one or more partition modes of a geometric partitioning mode (GEO), where there are M partition modes of GEO; constructing a mapping table having an index value indicating the partition mode based on the respective costs for the one or more partition modes of GEO; determining the partition mode based on the mapping table; and reconstructing a current block of the video data based on the determined partition mode.

[0364]

[0370] Clause 28. The method of clause 27, wherein the cost is a template matching (TM) cost.

[0365]

[0371] Clause 29. The method of any of clauses 27 and 28, wherein constructing the mapping table includes ordering the one or more partitioning modes in ascending order based on their respective costs.

[0366]

[0372] Clause 30. The method of any of clauses 27 and 28, wherein constructing the mapping table includes including the N partitioning modes having the lowest costs.

[0367]

[0373] Clause 31. The method of clause 30, wherein the value of N is based on a size of the current block.

[0368]

[0374] Clause 32. A method as described in any of clauses 27 to 31, wherein reconstructing the current block based on the determined partition mode includes determining a first set of predicted values ​​for a first partition of the current block defined by the determined partition mode, determining a second set of predicted values ​​for a second partition of the current block defined by the determined partition mode, determining residual values ​​of the current block, and reconstructing the current block based on the first set of predicted values, the second set of predicted values, and the residual values.

[0369]

[0375] Clause 33. A method for encoding video data, comprising: determining a cost associated with one or more partition modes of a geometric partitioning mode (GEO), where there are M partition modes of GEO; constructing a mapping table having index values ​​indicative of the partition modes based on the respective costs for the one or more partition modes of GEO; determining the partition mode based on the mapping table; and signaling an index to the mapping table indicative of the partition mode for decoding a current block of video data.

[0370]

[0376] Clause 34. The method of clause 33, wherein the cost is a template matching (TM) cost.

[0371]

[0377] Clause 35. The method of any of clauses 33 and 34, wherein constructing the mapping table includes ordering the one or more partitioning modes in ascending order based on their respective costs.

[0372]

[0378] Clause 36. The method of any of clauses 33 and 34, wherein constructing the mapping table includes including the N partitioning modes having the lowest costs.

[0373]

[0379] Clause 37. The method of clause 36, wherein the value of N is based on a size of the current block.

[0374]

[0380] Clause 38. A device for decoding video data, comprising: a memory; and a processing circuit coupled to the memory and configured to perform the method according to any of clauses 27 to 32.

[0375]

[0381] Clause 39. The device of clause 38, further comprising a display configured to display the decoded video data.

[0376]

[0382] Clause 40. A device according to any of clauses 38 and 39, wherein the device comprises one or more of a camera, a computer, a mobile device, a broadcast receiver device, or a set-top box.

[0377]

[0383] Clause 41. A computer-readable storage medium storing instructions that, when executed, cause one or more processors to perform the method of any of clauses 27 to 32.

[0378]

[0384] Clause 42. A device for decoding video data, comprising means for performing the method according to any of clauses 27 to 32.

[0379]

[0385] Clause 43. A device for encoding video data, comprising a memory and a processing circuit configured to perform the method according to any of clauses 33 to 37.

[0380]

[0386] Clause 44. The device of clause 43, further comprising a camera configured to capture video data.

[0381]

[0387] Clause 45. A computer-readable storage medium storing instructions which, when executed, cause one or more processors to perform the method of any of clauses 33 to 37.

[0382]

[0388] Clause 46. A device for encoding video data, comprising means for performing the method according to any of clauses 33 to 37.

[0383]

[0389] Clause 1A. A method for encoding or decoding video data, comprising: determining that a geometric partitioning mode is enabled for a current block of video data, the geometric partitioning mode including a plurality of partitioning modes each defining an edge for partitioning; determining, for each partitioning mode among at least two of the plurality of partitioning modes, a respective cost associated with the respective partitioning mode; constructing a mapping list including index values ​​respectively associated with values ​​indicative of the respective partitioning modes based on the respective costs associated with the respective partitioning modes, wherein a lower index value in the mapping list is associated with a first partitioning mode having a lower cost than a second partitioning mode having a higher index value in the mapping list; determining a partitioning mode from among the plurality of partitioning modes in the mapping list; and reconstructing the current block of video data based on the partitioning mode.

[0384]

[0390] Clause 2A. The method of clause 1A, wherein determining respective costs associated with each partition mode includes determining a respective reference template based on the respective partition mode, determining a current template for the current block, the current template including a sample outside the current block, and determining respective costs associated with each partition mode based on the respective reference template and the current template.

[0385]

[0391] Clause 3A. The method of clause 2A, wherein determining each reference template includes determining a first reference template based on a first reference block identified by a first motion vector of a first partition of the current block, determining a second reference template based on a second reference block identified by a second motion vector of a second partition of the current block, and combining samples from the first reference template and samples from the second reference template based on the respective partition modes to generate the respective reference templates.

[0386]

[0392] Clause 4A. The method of clause 3A, wherein the first reference template includes a first portion of samples above the first reference block and a second portion of samples to the left of the first reference block, and the second reference template includes a first portion of samples above the second reference block and a second portion of samples to the left of the second reference block.

[0387]

[0393] Clause 5A. The method of any of clauses 3A and 4A, wherein combining samples from the first reference template and samples from the second reference template based on respective partition modes to generate respective reference templates includes applying respective partition modes to the first reference block; extending the applied respective partition modes to samples of the first reference template to generate a first set of samples in the first reference template and a second set of samples in the first reference template; accessing the first set of samples in the first reference template based on the extension of the applied respective partition modes to the samples of the first reference template; applying the respective partition modes to the second reference block; extending the applied respective partition modes to samples of the second reference template to generate a third set of samples in the second reference template and a fourth set of samples in the second reference template; accessing a third set of samples in the second reference template based on the extension of the applied respective partition modes to the samples of the second reference template; and combining the first set of samples and the third set of samples to generate respective reference templates.

[0388]

[0394] Clause 6A. The method of clause 5A, wherein combining the first set of samples and the third set of samples to generate respective reference templates includes blending one or more samples in the first set of samples with one or more samples in the fourth set of samples, blending one or more samples in the third set of samples with one or more samples in the second set of samples, and combining the first set of samples and the third set of samples based on the blending.

[0389]

[0395] Clause 7A. The method of any of clauses 1A-6A, further comprising receiving an index value indicating a split mode; and determining the split mode based on the index value into the mapping list.

[0390]

[0396] Clause 8A. The method of clause 7A, wherein receiving the index value includes at least one of: fixed-length binary decoding information indicative of the index value; truncated binary decoding information indicative of the index; Golomb-Rice decoding information indicative of the index value; and context-based adaptive coding (CABAC) decoding one or more bins of the information indicative of the index value, including examples in which some of the one or more bins are CABAC decoded and others are bypass decoded, and examples in which all bins are CABAC decoded.

[0391]

[0397] Clause 9A. The method of any of clauses 1A-8A, wherein constructing the mapping list includes ordering one or more of the plurality of partitioning modes in ascending order of index values ​​based on their respective costs.

[0392]

[0398] Clause 10A. The method of any of clauses 1A-9A, wherein constructing the mapping list includes including N partition modes of the plurality of partition modes having the lowest costs.

[0393]

[0399] Clause 11A. The method of any of clauses 1A to 10A, wherein the current block is of a first picture, the current block is the first block, and the method further includes determining that a geometric partitioning mode is enabled for a second block of a second picture of the video data, determining that a size of at least one reference picture for the second block is different from a size of the second picture, and bypassing the partition mode reordering process based on a determination that the size of the at least one reference picture is different from the size of the second picture.

[0394]

[0400] Clause 12A. The method of any one of clauses 1A to 11A, further comprising signaling an index value indicating the split mode.

[0395]

[0401] Clause 13A. A device for encoding or decoding video data, the device comprising: a memory configured to store the video data; and a processing circuit coupled to the memory, the processing circuit configured to: determine that a geometric partitioning mode is enabled for a current block of video data, the geometric partitioning mode including a plurality of partitioning modes each defining an edge for partitioning; for each partitioning mode among at least two of the plurality of partitioning modes, a respective cost associated with the respective partitioning mode; construct a mapping list including index values ​​respectively associated with values ​​indicative of the respective partitioning modes based on the respective costs associated with the respective partitioning modes, a lower index value in the mapping list being associated with a first partitioning mode having a lower cost than a second partitioning mode having a higher index value in the mapping list; determine a partitioning mode among the plurality of partitioning modes in the mapping list; and reconstruct the current block of video data based on the partitioning mode.

[0396]

[0402] Clause 14A. The device of clause 13A, wherein to determine a respective cost associated with each division mode, the processing circuitry is configured to: determine a respective reference template based on the respective division mode; determine a current template for the current block, the current template including samples outside the current block; and determine a respective cost associated with each division mode based on the respective reference template and the current template.

[0397]

[0403] Clause 15A. The device of clause 14A, wherein to determine the respective reference templates, the processing circuitry is configured to determine a first reference template based on a first reference block identified by a first motion vector of a first partition of the current block, determine a second reference template based on a second reference block identified by a second motion vector of a second partition of the current block, and combine samples from the first reference template and samples from the second reference template based on the respective partition modes to generate the respective reference templates.

[0398]

[0404] Clause 16A. A device as described in clause 15A, wherein the first reference template includes a first portion of samples above the first reference block and a second portion of samples to the left of the first reference block, and the second reference template includes a first portion of samples above the second reference block and a second portion of samples to the left of the second reference block.

[0399]

[0405] Clause 17A. The device of any of clauses 15A and 16A, wherein the processing circuit is configured to: apply the respective division modes to the first reference block, extend the applied respective division modes to samples of the first reference template to generate a first set of samples in the first reference template and a second set of samples in the first reference template, access the first set of samples in the first reference template based on the extension of the applied respective division modes to the samples of the first reference template, apply the respective division modes to the second reference block, extend the applied respective division modes to samples of the second reference template to generate a third set of samples in the second reference template and a fourth set of samples in the second reference template, access the third set of samples in the second reference template based on the extension of the applied respective division modes to the samples of the second reference template, and combine the first set of samples and the third set of samples to generate the respective reference templates.

[0400]

[0406] Clause 18A. The device of clause 17A, wherein the processing circuitry is configured to blend one or more samples in the first set of samples with one or more samples in the fourth set of samples, blend one or more samples in the third set of samples with one or more samples in the second set of samples, and combine the first set of samples with the third set of samples based on the blending to combine the first set of samples and the third set of samples to generate respective reference templates.

[0401]

[0407] Clause 19A. A device as described in any of clauses 13A to 18A, wherein the processing circuitry is configured to receive an index value indicating the split mode, and determine the split mode based on the index value into the mapping list.

[0402]

[0408] Clause 20A. The device of clause 19A, wherein to receive the index value, the processing circuitry is configured to perform at least one of: fixed-length binary decoding of information indicative of the index value, truncated binary decoding of information indicative of the index value, Golomb-Rice decoding of information indicative of the index value, or context-based adaptive coding (CABAC) decoding of one or more bins of information indicative of the index value.

[0403]

[0409] Clause 21A. A device as described in any of clauses 13A to 20A, wherein to construct the mapping list, the processing circuitry is configured to order one or more of the plurality of partition modes in ascending order of index value based on their respective costs.

[0404]

[0410] Clause 22A. The device of any of clauses 13A to 21A, wherein to construct the mapping list, the processing circuitry is configured to include N partition modes of the plurality of partition modes having the lowest cost.

[0405]

[0411] Clause 23A. The device of any of clauses 13A to 22A, wherein the current block is of a first picture and the current block is the first block, and the processing circuitry is configured to determine that a geometric partitioning mode is enabled for a second block of a second picture of the video data, determine that a size of at least one reference picture for the second block is different from a size of the second picture, and bypass the partition mode reordering process based on a determination that the size of the at least one reference picture is different from the size of the second picture.

[0406]

[0412] Clause 24A. The device of any of clauses 13A to 23A, wherein the processing circuitry is configured to signal an index value indicating the split mode.

[0407]

[0413] Clause 25A. A computer-readable storage medium storing instructions which, when executed, cause one or more processors for encoding or decoding video data to determine that a geometric partitioning mode is enabled for a current block of video data, the instructions including a plurality of partitioning modes each defining an edge for partitioning; for each partitioning mode among at least two of the plurality of partitioning modes, a respective cost associated with the respective partitioning mode; construct a mapping list including index values ​​respectively associated with values ​​indicative of the respective partitioning modes based on the respective costs associated with the respective partitioning modes, a lower index value in the mapping list being associated with a first partitioning mode having a lower cost than a second partitioning mode having a higher index value in the mapping list; determine a partitioning mode among the plurality of partitioning modes in the mapping list; and reconstruct the current block of video data based on the partitioning mode.

[0408]

[0414] Clause 26A. The computer-readable storage medium of clause 25A, wherein the instructions for causing one or more processors to determine respective costs associated with the respective partition modes include instructions for causing the one or more processors to determine respective reference templates based on the respective partition modes, determine a current template for a current block, the current template including samples outside the current block, and determine respective costs associated with the respective partition modes based on the respective reference templates and the current template.

[0409]

[0415] Clause 27A. The computer-readable storage medium of clause 26A, wherein the instructions for causing the one or more processors to determine respective reference templates include instructions for causing the one or more processors to determine the first reference template based on a first reference block identified by a first motion vector of a first partition of the current block, determine a second reference template based on a second reference block identified by a second motion vector of a second partition of the current block, and combine samples from the first reference template and samples from the second reference template based on the respective partition modes to generate the respective reference templates.

[0410]

[0416] Clause 28A. A computer-readable storage medium as described in clause 27A, wherein the first reference template includes a first portion of samples above the first reference block and a second portion of samples to the left of the first reference block, and the second reference template includes a first portion of samples above the second reference block and a second portion of samples to the left of the second reference block.

[0411]

[0417] Clause 29. Instructions for causing the one or more processors to combine samples from the first reference template and samples from the second reference template based on respective partition modes to generate respective reference templates, instructions for causing the one or more processors to apply respective partition modes to the first reference template, extend the applied respective partition modes to samples of the first reference template to generate a first set of samples in the first reference template and a second set of samples in the first reference template, and extend the applied respective partition modes to samples of the first reference template based on the extension of the applied respective partition modes to the samples of the first reference template to generate a first set of samples in the first reference template and a second set of samples in the first reference template. The computer-readable storage medium of any of clauses 27A and 28A, comprising instructions to access the first set of samples in the second reference template, apply the respective partitioning modes to the second reference block, extend the applied respective partitioning modes to the samples of the second reference template to generate a third set of samples in the second reference template and a fourth set of samples in the second reference template, access the third set of samples in the second reference template based on the extension of the applied respective partitioning modes to the samples of the second reference template, and combine the first set of samples and the third set of samples to generate the respective reference template.

[0412]

[0418] Clause 30A. The computer-readable storage medium of clause 29A, wherein the instructions for causing one or more processors to combine the first set of samples and the third set of samples to generate respective reference templates include instructions for causing the one or more processors to blend one or more samples in the first set of samples with one or more samples in the fourth set of samples, blend one or more samples in the third set of samples with one or more samples in the second set of samples, and combine the first set of samples with the third set of samples based on the blending.

[0413]

[0419] Clause 31A. A computer-readable storage medium according to any of clauses 25A to 30A, further comprising instructions for causing one or more processors to receive an index value indicating a partitioning mode and determine the partitioning mode based on the index value into the mapping list.

[0414]

[0420] Clause 32A. A computer-readable storage medium as described in any of clauses 25A to 31A, wherein the instructions for causing one or more processors to receive an index value include instructions for causing one or more processors to perform at least one of: fixed-length binary decoding of information indicative of the index value; truncated binary decoding of information indicative of the index value; Golomb-Rice decoding of information indicative of the index value; or context-based adaptive coding (CABAC) decoding of one or more bins of information indicative of the index value.

[0415]

[0421] Clause 33A. A computer-readable storage medium according to any one of clauses 25A to 32A, wherein the instructions for causing one or more processors to construct the mapping list include instructions for causing the one or more processors to order one or more of the plurality of partition modes in ascending order of index values ​​based on their respective costs.

[0416]

[0422] Clause 34A. A computer-readable storage medium according to any one of clauses 25A to 33A, wherein the instructions for causing one or more processors to construct a mapping list include instructions for causing the one or more processors to include N partition modes among a plurality of partition modes having the lowest costs.

[0417]

[0423] Clause 35A. A computer-readable storage medium as described in any of clauses 25A to 34A, further comprising instructions for causing the one or more processors to determine that a geometric partitioning mode is enabled for a second block of a second picture of the video data, determine that a size of at least one reference picture for the second block is different from a size of the second picture, and bypass the partition mode reordering process based on a determination that the size of the at least one reference picture is different from the size of the second picture.

[0418]

[0424] Clause 36A. The computer-readable storage medium of any of clauses 25A to 35A, wherein the instructions further include instructions for causing one or more processors to signal an index value indicating the split mode.

[0419]

[0425] Clause 37A. A device for encoding or decoding video data, comprising: means for determining that a geometric partitioning mode is enabled for a current block of video data, the geometric partitioning mode including a plurality of partitioning modes each defining an edge for partitioning; means for determining, for each partitioning mode among at least two of the plurality of partitioning modes, a respective cost associated with the respective partitioning mode; means for constructing a mapping list including index values ​​respectively associated with values ​​indicative of the respective partitioning modes based on the respective costs associated with the respective partitioning modes, wherein a lower index value in the mapping list is associated with a first partitioning mode having a lower cost than a second partitioning mode having a higher index value in the mapping list; means for determining a partitioning mode from among the plurality of partitioning modes in the mapping list; and means for reconstructing the current block of video data based on the partitioning mode.

[0420]

[0426] Clause 38A. The device of clause 37A, wherein the means for determining respective costs associated with each partition mode comprises: means for determining a respective reference template based on the respective partition mode; means for determining a current template for a current block, the current template including samples outside the current block; and means for determining respective costs associated with each partition mode based on the respective reference template and the current template.

[0421]

[0427] Clause 39A. The device of clause 38A, wherein the means for determining each reference template comprises: means for determining a first reference template based on a first reference block identified by a first motion vector of a first partition of the current block; means for determining a second reference template based on a second reference block identified by a second motion vector of a second partition of the current block; and means for combining samples from the first reference template and samples from the second reference template based on the respective partition modes to generate the respective reference templates.

[0422]

[0428] Clause 40A. A device as described in clause 39A, wherein the first reference template includes a first portion of samples above the first reference block and a second portion of samples to the left of the first reference block, and the second reference template includes a first portion of samples above the second reference block and a second portion of samples to the left of the second reference block.

[0423]

[0429] Clause 41A. Means for combining samples from a first reference template and samples from a second reference template based on respective partition modes to generate respective reference templates, means for applying respective partition modes to the first reference block, means for extending the applied respective partition modes to samples of the first reference template to generate a first set of samples in the first reference template and a second set of samples in the first reference template, and means for accessing the first set of samples in the first reference template based on the extension of the applied respective partition modes to the samples of the first reference template. The device described in any of clauses 39A and 40A, comprising: a first reference block stage; means for applying the respective division modes to the second reference block; means for extending the applied respective division modes to samples of the second reference template to generate a third set of samples in the second reference template and a fourth set of samples in the second reference template; means for accessing the third set of samples in the second reference template based on the extension of the applied respective division modes to the samples of the second reference template; and means for combining the first set of samples and the third set of samples to generate the respective reference template.

[0424]

[0430] Clause 42A. The device of clause 41A, wherein the means for combining the first set of samples and the third set of samples to generate a respective reference template comprises: means for blending one or more samples in the first set of samples with one or more samples in the fourth set of samples; means for blending one or more samples in the third set of samples with one or more samples in the second set of samples; and means for combining the first set of samples and the third set of samples based on the blending.

[0425]

[0431] Clause 43A. The device of any of clauses 37A to 42A, further comprising: means for receiving an index value indicating a split mode; and means for determining the split mode based on the index value into the mapping list.

[0426]

[0432] Clause 44A. The device of clause 43A, wherein the means for receiving the index value comprises at least one of: means for fixed length binary decoding information indicative of the index value, means for truncated binary decoding information indicative of the index value, means for Golomb-Rice decoding information indicative of the index value, or means for context-based adaptive coding (CABAC) decoding one or more bins of the information indicative of the index value.

[0427]

[0433] Clause 45A. A device as described in any of clauses 37A to 44A, wherein the means for constructing the mapping list comprises means for ordering one or more of the plurality of partition modes in ascending order of index value based on their respective costs.

[0428]

[0434] Clause 46A. The device of any of clauses 37A to 45A, wherein the means for constructing the mapping list comprises means for including N split modes of the plurality of split modes having the lowest cost.

[0429]

[0435] Clause 47A. A device as described in any of clauses 37A to 46A, wherein the current block is of a first picture and the current block is the first block, and the device further comprises: means for determining that a geometric partitioning mode is enabled for a second block of a second picture of the video data; means for determining that a size of at least one reference picture for the second block is different from a size of the second picture; and means for bypassing the partition mode reordering process based on a determination that the size of the at least one reference picture is different from the size of the second picture.

[0430]

[0436] Clause 48A. The device of any of clauses 37A to 47A, further comprising means for signaling an index value indicating a split mode.

[0431]

[0437] By way of example, it should be appreciated that any acts or events of the techniques described herein may be performed in a different order, may be added, combined, or omitted entirely (e.g., not all acts or events described are necessary to the practice of the techniques). Moreover, in some examples, acts or events may be performed in parallel rather than sequentially, for example, through multithreaded processing, interrupt processing, or multiple processors.

[0432]

[0438] In one or more examples, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted via a computer-readable medium as one or more instructions or code and executed by a hardware-based processing unit. A computer-readable medium may include a computer-readable storage medium, which corresponds to a tangible medium, such as a data storage medium, or a communication medium, which includes any medium that facilitates transfer of a computer program from one place to another, for example, according to a communication protocol. As such, a computer-readable medium may generally correspond to (1) a tangible computer-readable storage medium that is non-transitory, or (2) a communication medium, such as a signal or carrier wave. A data storage medium may be any available 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. A computer program product may include a computer-readable medium.

[0433]

[0439] By way of example, and not limitation, such computer-readable storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly referred to as a computer-readable medium. For example, if 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, the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included within the definition of the medium. However, it should be understood that computer-readable storage media and data storage media do not include connections, carrier waves, signals, or other transitory media, but instead refer to non-transitory, tangible storage media. As used herein, disk and disc include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, where disks typically reproduce data magnetically and discs reproduce data optically using lasers. Combinations of the above are also intended to be included within the scope of computer readable media.

[0434]

[0440] 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 circuitry. Accordingly, the terms "processor" and "processing circuitry" as used herein may refer to any of the above structures, or any other structure suitable for implementing the techniques described herein. In addition, in some aspects, the functionality described herein may be provided within dedicated hardware and / or software modules configured for encoding and decoding, or may be incorporated into a combined codec. The techniques may also be fully implemented in one or more circuits or logic elements.

[0435]

[0441] The techniques of this disclosure may be implemented in a wide variety of devices or apparatuses, including a wireless handset, an integrated circuit (IC), or a set of ICs (e.g., a chipset). Various components, modules, or units are described in this disclosure to highlight functional aspects of devices configured to implement the disclosed techniques, but do not necessarily require realization by different hardware units. Rather, as described above, the various units may be combined in a codec hardware unit or may be provided by a collection of interoperable hardware units including one or more processors as described above, in conjunction with suitable software and / or firmware.

[0436]

[0442] Various examples have been described. These and other examples are within the scope of the following claims.

Claims

1. 1. A method for encoding or decoding video data, comprising: determining that a geometric partitioning mode is enabled for a current block of video data, the geometric partitioning mode including a plurality of partitioning modes each defining an edge for partitioning; determining, for each partitioning mode among at least two of the plurality of partitioning modes, a respective cost associated with the respective partitioning mode; constructing a mapping list including index values ​​respectively associated with values ​​indicative of the respective partition modes based on the respective costs associated with the respective partition modes, wherein a lower index value in the mapping list is associated with a first partition mode having a lower cost than a second partition mode having a higher index value in the mapping list; determining a partitioning mode from among the plurality of partitioning modes in the mapping list; reconstructing the current block of video data based on the partition mode; and A method comprising:

2. determining the respective costs associated with the respective partitioning modes; determining a respective reference template based on the respective segmentation mode; determining a current template for the current block, the current template including samples outside the current block; determining the respective costs associated with the respective partitioning modes based on the respective reference templates and the current template; The method of claim 1 , comprising:

3. determining each of the reference templates, determining a first reference template based on a first reference block identified by a first motion vector of a first partition of the current block; determining a second reference template based on a second reference block identified by a second motion vector of a second partition of the current block; combining samples from the first reference template and samples from the second reference template based on the respective division modes to generate the respective reference templates; The method of claim 2 , comprising:

4. 4. The method of claim 3, wherein the first reference template includes a first portion of samples above the first reference block and a second portion of samples to the left of the first reference block, and the second reference template includes a first portion of samples above the second reference block and a second portion of samples to the left of the second reference block.

5. combining samples from the first reference template and samples from the second reference template based on the respective division modes to generate the respective reference templates; applying the respective partitioning modes to the first reference block; extending the applied respective decomposition modes to samples of the first reference template to generate a first set of samples in the first reference template and a second set of samples in the first reference template; accessing a first set of the samples in the first reference template based on the extension of the applied respective segmentation mode to the samples of the first reference template; applying the respective partitioning modes to the second reference block; extending each of the applied decomposition modes to samples of the second reference template to generate a third set of samples in the second reference template and a fourth set of samples in the second reference template; accessing a third set of the samples in the second reference template based on the extension of the applied respective segmentation modes to the samples of the second reference template; combining the first set of samples and the third set of samples to generate the respective reference templates; The method of claim 3, comprising:

6. combining the first set of samples with the third set of samples to generate the respective reference templates; blending one or more samples in the first set of samples with one or more samples in the fourth set of samples; blending one or more samples in the third set of samples with one or more samples in the second set of samples; combining the first set of samples and the third set of samples based on the blending; The method of claim 5 , comprising:

7. receiving an index value indicating the split mode; determining the partitioning mode based on the index value into the mapping list; The method of claim 1 further comprising:

8. receiving the index value, performing fixed-length binary decoding of the information indicating the index value; truncated binary decoding information indicative of the index value; Golomb-Rice decoding the information indicative of the index value; or Context-based adaptive coding (CABAC) decoding one or more bins of information indicative of the index value; The method of claim 7 , comprising at least one of:

9. 2. The method of claim 1, wherein constructing the mapping list comprises ordering one or more of the plurality of partitioning modes based on the respective costs in ascending order of the index values.

10. The method of claim 1 , wherein constructing the mapping list includes including N partitioning modes of the plurality of partitioning modes that have the lowest costs.

11. The current block is of a first picture, and the current block is a first block, and the method comprises: determining that a geometric partitioning mode is enabled for a second block of a second picture of the video data; determining that a size of at least one reference picture for the second block is different from a size of the second picture; bypassing a partition mode reordering process based on the determination that the size of the at least one reference picture is different from the size of the second picture; The method of claim 1 further comprising:

12. The method of claim 1 , further comprising signaling an index value indicating the splitting mode.

13. 1. A device for encoding or decoding video data, comprising: a memory configured to store video data; a processing circuit coupled to the memory; wherein the processing circuitry comprises: determining that a geometric partitioning mode is enabled for the current block of video data, the geometric partitioning mode including a plurality of partitioning modes each defining an edge for partitioning; determining, for each partitioning mode among at least two of the plurality of partitioning modes, a respective cost associated with the respective partitioning mode; constructing a mapping list including index values ​​respectively associated with values ​​indicative of the respective partition modes based on the respective costs associated with the respective partition modes, a lower index value in the mapping list being associated with a first partition mode having a lower cost than a second partition mode having a higher index value in the mapping list; determining a partition mode from among the plurality of partition modes in the mapping list; reconstructing the current block of video data based on the partition mode; It is configured as follows: device.

14. The device of claim 13, further configured to perform a method according to any one of claims 2 to 12.

15. 13. A computer-readable storage medium storing instructions that, when executed, cause one or more processors for encoding or decoding video data to perform the method of any one of claims 1 to 12.

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